CEC Abstracts in PDF format (as of 7/3/07) - CEC-ICMC 2013

CEC 2007 - Abstracts 

CEC Sessions 

Tuesday, 07/17/07 Poster 

9:00am - 10:30am 

C1-B JT, Magnetic and Non-Aerospace 

Coolers 

C1-B-01 Development of JT Coolers Operating at 

Cryogenic Temperatures with Non-Flammable Mixed 

Refrigerants 

A.N. Khatri, M. Boiarski, Advanced Research 

Systems. Inc.. 

Throttle cycle coolers, operating with mixed refrigerants (MR) have 

been used in applications at temperatures down to 70 K. Industrial 

single-stage, oil lubricated compressor can be used to provide both a 

relatively low cost and long operational time. Application of 

nonflammable MR is important for safety, transportation, operation, 

service and maintenance. However, it is more difficult to provide a 

required refrigeration performance and long-term reliability due to 

properties of nonflammable MR. 

The paper presents experimental and modeling data for single-stage 

coolers providing up to 10 W of refrigeration capacity. The selected 

nonflammable components to build the MR are commercially 

available. 

A comparative experimental and modeling performance data is 

presented for both flammable and nonflammable MR. A gas 

refrigerant supply (GRS) technology is used for a single-stage cooler 

design. A minimal achievable temperature is restricted by the freezing 

point of MR. The GRS technology restricts a maximal refrigeration 

capacity. However, it allows to compromise between stable, long-term 

reliable operation and simplicity of equipment design with required 

refrigeration capacity. 

Stability of operation of small-scale, highly reliable MR coolers has 

been proven by the data accumulated over long-term testing. 

C1-B-02 Experimental Investigations on Mixed 

Refrigerant Joule-Thomson (MR J-T) Cryocooler 

N.S. Walimbe, M.D. Atrey, Indian Institute of 

Technology Bombay, Mumbai,India; K.G. 

Narayankhedkar, Veermata Jijabai Technological 

Institute, Mumbai,India. 

Mixed Refrigerant Joule Thomson (MR J-T) cryoocoolers have 

obvious advantages, such as low cost, high reliability, higher cooling 

effect at 80 K, low vibrations and simplicity in design layout. As a 

result of this, their use for different applications has become a major 

threat to conventional cryocoolers. 

The performance of the MR J-T cryocooler, in terms of cooling power 

at low temperatures, depends significantly on the components of the 

gas mixture and their concentration. An experimental set up has been 

developed in our laboratory to analyse various gas mixtures. An 

efficient counter flow heat exchanger, Hampson type, has been 

fabricated and tested in the set up. The present paper gives 

experimental results for various gas mixtures so as to get maximum 

cooling effect for a given temperature. The paper also presents the 

effect of working pressure of the optimized gas mixture on the 

performance of the cooler. 

C1-B-03 Performance of a mixed refrigerant Nitrogen gas 

cooler 

M. Siva Sankar, G. Venkatarathnam, Indian Institute 

of Technology Madras. 

Mixed refrigerant processes are widely used for the liquefaction of 

natural gas. J-T cryocoolers operating with refrigerant mixtures are 

also being developed worldwide. Mixed refrigerant processes can also 

be used for the liquefaction of air, nitrogen etc. A number of patents 

have been granted on the liquefaction of nitrogen using non 

flammable mixtures recently. Two large commercial mixed refrigerant 

precooled air separation plants have also been tested recently [1]. 

Nitrogen gas coolers operating with mixtures of nitrogen, methane, 

ethane, propane etc. are under development in our laboratory. 

In this paper we describe the performance of our prototype nitrogen 

gas cooler. The system comprises of a pre-cooling circuit and a mixed 

refrigerant circuit. Tests have been carried out with different nitrogen 

flow rates, different refrigerant mixtures and heat exchangers. In the 

current prototype, nitrogen can be cooled from room temperature to 

about 105 K at a flow rate of 0.1 g/s. The power input to the system is 

about 1200 W. The performance of our system and comparison 

between experimental results and simulations are also presented. 

References 

1) Bonaquist, D..P., Prosser, N.M., and Arman, B. (2003). Advances 

in refrigeration for air separation --- using mixed refrigerant cycles 

toreduce cost and improve efficiency, Paper ICR0524, Proceedings of 

the International Congress of Refrigeration 2003, Washington D.C., p 

1-7. 

C1-B-04 Pressure drop and heat transfer characteristics 

in a helical tube of Joule Thomson refrigerator 

Y-J. Hong, S-J. Park, Korea Institute of Machinery & 

Materials; Y-D. Choi, Korea University. 

The thermodynamic performance of a miniature Joule Thomson 

refrigerator is highly depends on the hydraulic and heat transfer 

characteristics of the recuperative heat exchanger. The typical 

recuperative heat exchanger has the double helical tube and fin 

configuration. The incoming high-pressure gas enters a helical tube, 

and expands to the cold end of the refrigerator. After the Joule- 

Thomson expansion, the cold gas exhausts through a complex passage 

that is enveloped by the double helical tube and fin, mandrel and inner 

surface of the Dewar. The present study focuses on the pressure drop 

and heat transfer characteristics in the helical tube. In general way, the 

curvature ratio of the helical tube has substantial influences on the 

pressure drop and heat transfer characteristics. In this study, the heat 

and fluid flow is studied numerically on the high pressure gas in a 

helical tube. To account for the thermodynamic properties of the high 

pressure gas, the real gas model as a function of pressure and 

temperature was used. The effects of the mass flow rate, heat flux, 

pitch of the tubes and curvature ratio were studied by commercial 

CFD packages. 

C1-B-05 A Study of Active Magnetic Regeneration using 

Permanent Magnets 

S. Kito, K. Kamiya, H. Nakagome, S. Uchimoto, Chiba 

University; T. Kobayashi, A. Takahashi Saito, S. Kaji, 

Toshiba Corporation. 

In recent years, magnetic refrigeration techniques based on the 

magnetocaloric effect attracts attention from a viewpoint of earth 

environment protection, because the magnetic refrigeration is 

technology with little environmental load in order not to use 

chlorofluorocarbons. Especially, a new type of refrigeration cycle, the 

active magnetic regenerator (AMR) cycle, is suitable for a room 

temperature region, and the AMR cycle is expected to attain high 

efficiency. 

We developed a room temperature magnetic refrigerator with 

permanent magnets, and operated the AMR cycle by using Gd and 

Gd-R alloys for the magnetic refrigerant. The AMR cycle with 

changing in the magnetic field and a movement of the heat transfer 

fluid was operated for various parameters such as cycle frequency, 

amount of the heat transfer fluid movement, etc. 

Page 1 of 53


In this report, we will show the result of the observing temperatures 

span ( - Tmax) between hot end and cold end in the heat exchanger 

while the AMR cycle operation and the temperature gradient of 

magnetic refrigerant in the heat exchanger, in which several 

thermocouples were inserted. - Tmax is depending on cycle 

frequency of the AMR. Moreover, a numerical analysis of the AMR 

cycle was performed in order to investigate the correspondence to the 

experimental result. It was revealed that - Tmax increased with the 

cycle frequency, and almost agreed to the calculation result. 

C1-B-06 Magnetocaloric Effect of Sintered GGG 

D.L. Kim, B.S. Lee, Y.S. Choi, H.S. Yang, Korea Basic 

Science Institute; S.H. Yeom, Chungnam National 

University; J.H. Park, Korea Astronomy & Space 

Science Institute. 

Magnetic cooling is one of the effective method to get low 

temperature without cryogen. 

GGG is a good candidate material to reach ~1K after precooled by 

cryocooler. GGG sample is made by sintering the granular type of 

GGG. The sample is tested the magneto-caloric effect in various 

magnetic field and temperature conditions with PPMS that has a 9T 

superconducting magnet and minimum temperature of 1.5K. The 

results of the magnetocaloric experiments are presented. 

C1-B-07 Scaling of thermoacoustic refrigerators 

Y. Li, J.C.H. Zeegers, H.J.M. ter Brake, Eindhoven 

University of Technology. 

Thermoacoustic refrigerators pump heat from a low-temperature 

source to a high-temperature sink using acoustics. Their simplicity 

leads to high reliability and low cost, which is attractive for practical 

applications. However, very large dimensions are common for 

thermoacoustic machines of order 10 m. In the paper, the possibility 

of scaling-down thermoacoustc refrigerators is investigated via 

theoretical analysis. Standing-wave systems are considered as well as 

travelling-wave. In the case of standing-wave refrigerators, a 

reference system is taken that consists of a resonator tube (25 cm) 

with a closed end and a PVC stack (length 5 cm). Helium is used at a 

mean pressure of 1 bar and an amplitude of 0.1 bar. The resulting 

operating frequency is 1 kHz. The variation of the performance of the 

refrigerator when scaled down is computed under the prerequisites 

that the temperature difference over the stack or energy flux or energy 

flux density are fixed. The analytical results show, as expected, that 

there is a limitation for scaling-down of a standing-wave 

thermoacoustic refrigerator due to heat conduction. In the paper, 

trends are discussed as well as means to widen the scaling range. 

Furthermore, similar scaling trends are considered in travelling-wave 

refrigerators, again with thermal conductance forming a practical 

limitation. 

C1-B-08 Performance improvement of a single stage GM 

cryocooler at 25 K 

C. Wang, P.E. Gifford, Cryomech, Inc.. 

Some HTS applications, such as motor and generator, require large 

cooling capacity at 25-27 K. Cryomech, Inc. has redesigned and 

improved a single stage GM cryocooler, model AL330, to have 

maximum capacity at 25K. The losses for the low temperature single 

stage GM have been analyzed. In the new design, the losses 

associated with rotary valve, shuttle heat transfer, seals and 

regenerator, have been reduced. A 10 kW compressor, model 

CP1010, is employed for the new designed single stage GM 

cryocooler, model AL325. The AL325 reaches the bottom 

temperature of 10 K and provides a cooling capacity of >100W@25K. 

C1-B-09 Experimental study on the double-evaporator 

thermosiphon for cooling HTS (High Temperature 

Superconductor) system 

J. Lee, Y. Kim, S. Jeong, KAIST. 

Cryogenic thermosiphons are highly efficient heat transfer elements 

between a cryocooler and the thermal load that is to be cooled. This 

paper presents an idea of thermosiphon that peculiarly utilizes two 

evaporators to satisfy spatial restriction. The single condenser that is 

made of copper with the inner diameter of 42 mm is cooled by a GM 

cryocooler and the fallen liquid film from the condenser stays at the 

evaporator 1 (the upper evaporator). As the liquid pool of the 

evaporator 1 is full to its brim, the liquid film goes down from the 

evaporator 1 to the evaporator 2 (the lower evaporator). In the 

experiment, these copper evaporators are electrically heated to 

simulate their realistic cooling load conditions for the HTS (High 

Temperature Superconductor) system. The double-evaporator 

thermosiphon is to be used for cooling two HTS bulk parts that are 

separated vertically. Since nitrogen is the proper working fluid of the 

thermosiphon in this application, we selected the operating 

temperature and pressure as 70 K and 38.5 kPa respectively. We 

report the experimental results of this sub-atmospherically operating 

thermosiphon by analyzing its dynamic performance with existing 

theories. The innovation can probably provide a simple and compact 

cooling solution to the HTS system. 

This work was supported by ETEP (Electric Power Technology 

Evaluation and Plannig) and KOSEF (Korea 

Science and Engineering Foundation) 

C1-B-10 Stirling-Type Pulse Tube Cryocooler with 1kW 

of Refrigeration at 77K 

S.A. Potratz, T.D. Abbott, K.B. Albaugh, M.C. 

Johnson, Praxair, Inc. 

A large capacity Stirling-type pulse tube cryocooler has been 

successfully developed by Praxair, Inc. Performance testing of 

prototype and initial production models of the pulse tube coldhead has 

demonstrated a refrigeration capacity of 1kW at 77K when a 20kW, 

dual-opposed pressure wave generator from CFIC, Inc. is used to 

generate acoustic power for the cryocooler. These results were 

obtained through multiple experiments utilizing gas liquefaction and 

direct nitrogen subcooling test methods. The coldhead design 

incorporates sophisticated geometry to successfully minimize 

streaming and other loss mechanisms that have reduced the 

performance of other large pulse tube cryocooler designs. These 

cryocoolers are intended for application in the HTS (High 

Temperature Superconductivity) market. The initial production 

models of this pulse tube refrigerator will be deployed for field testing 

at an operating HTS cable installation in Columbus, Ohio where their 

reliability and performance will be measured. 

C1-C Fluid Mechanics - I 

C1-C-01 Gravitational Capillary Viscometer for 

Subcooled Liquid Para-Hydrogen* 

M. Gnos, Y.K. Kim, D.K. Hilton, S.W. Van Sciver, 

NHMFL/FSU. 

A pressurized gravitational capillary viscometer was developed for 

subcooled low-temperature liquids, necessary for aerospace 

engineering. It acquires accurate absolute dynamic viscosity 

measurements with an uncertainty of 1% at a 95.5% confidence level, 

in the pressure domain from 0.15 MPa to 1.0 MPa, and in the 

temperature domain from the normal boiling point to near the freezing 

point. It has been modified by the addition of a two-stage ortho- to 

para-hydrogen converter. The converter uses a heat-treated, iron 

hydroxide powder catalyst, 25 g in the precooling first stage, and 1350 

g in the second stage that is thermally connected with the viscometer 

cell. The conversion is monitored with a calibrated platinum 

thermometer. Dynamic viscosity measurements for subcooled liquid 

para-hydrogen are presented. 

*Research supported by NASA Grant NAG 3-2751. 



C1-C-02 PIV Measurement of Slush Nitrogen Flow in 

Pipe Part II 

M Maeda, M Murakami, T Takakoshi, University of 

Tsukuba; M Ikeuchi, R Ono, K Matsuo, MAYEKAWA 

MFG. CO., LTD.. 

The use of slush nitrogen as a refrigerant for high-temperature 

superconductive power cable is considered to lead to further 

improvement in refrigerant capability. As the realization of a stable 

flow of slush nitrogen is a key technology for the application, the 

detailed investigation of flow characteristics is very important. This 

study primarily focuses on the measurement of the nitrogen particle 

velocity distribution in a circular test section. The application of PIV 

to the slush nitrogen flow in a pipe was initiated two years ago. In the 

previous study, the velocity in the boundary layer region could not be 

clearly resolved. In this experiment, some improvements were made 

with respect to the inner diameter and the cross sectional form of the 

test section to avoid the optical refraction effect for imaging. As a 

result, the velocity distribution even in the boundary layer of the test 

section could be fairly well resolved, and thus the whole solid particle 

velocity distribution throughout the cross section could be obtained. 

Furthermore, the application of minute particles of H2O instead of 

solid nitrogen is pursued for more systematic parametric study. The 

control of particle parameters of H2O is much more easily made, and 

the dynamic range of H2O particle parameters is wider than solid 

nitrogen particles. 

C1-C-03 Natural Circulation Loop of Subcooled Liquid 

Nitrogen 

M.J. Kim, H.M. Chang, Hong Ik University. 

An experimental study is performed to investigate the thermal and 

flow characteristics of subcooled liquid nitrogen in a natural 

circulation loop. This study is directed to a simple cryocooling system 

for small load HTS power applications, where a cryocooler should be 

installed on a separate cryostat and liquid nitrogen is circulated 

between the main and auxiliary cryostats. An experimental apparatus 

is designed and constructed such that a test loop made of circular tube 

with a uniform diameter is cooled at the top by a cryocooler and 

heated nearly at the bottom by cartridge heaters . Steady state is 

obtained by controlling the heating power to the cartridge heaters and 

a thin-film heater to reduce the cooling power of the cryocooler. 

Temperature is measured at several locations of the loop and the mass 

flow rate through the loop is estimated from the energy balance in 

terms of the measured temperatures. Experiment is repeated for 

various values of vertical height between the cooling and heating 

parts. The results show that the heat transfer capability of the loop has 

a maximum at a certain value of height. The optimal height to 

maximize the heat transfer is in a good agreement with our analytical 

prediction to take into account the buoyancy and viscous forces in the 

loop tube. 

This work is supported by the research funds from the Center for 

Applied Superconductivity Technology under the 21C Frontier R&D 

Program in Korea. 

C1-C-04 Pressure Drop Reduction of Slush Nitrogen in 

Turbulent Pipe Flows 

K. Ohira, Institute of Fluid Science, Tohoku 

University ; N. Koizumi, Tohoku University; J. 

Ishimoto, Institute of Fluid Science, Tohoku 

University; T. Kamiya, Mitsubishi Heavy Industries, 

Ltd.. 

Slush fluid such as slush hydrogen and slush nitrogen is a two-phase 

(solid-liquid) single-component cryogenic fluid containing solid 

particles in liquid, so that its density and cooling capacity increase 

compared with liquid state fluid. In this study, the experimental tests 

were performed with slush nitrogen (63 K) to obtain the frictional 

pressure drop characteristics flowing in a 15 mm internal diameter, 

625 mm long, horizontal, stainless steel pipe. The primary objective 

of this study is to investigate the pressure drop reduction phenomenon 

with the changes of the velocity and the solid fraction. From the 

experimental results, the pressure drop correlation between the 

friction factor and Reynolds number was obtained and an empirical 

equation was derived. Flow patterns and behaviors of solid particles 

were also observed by a high speed camera. 

C1-C-05 Numerical analysis of LN2 flow and thermal 

transfer in inner pipe of DC-SC power transmission line 

A. Sasaki, M. Hamabe, T. Famakinwa, S. Yamaguchi, 

Chubu University; A. Radovinsky, Massachusetts 

Institute of Technology; H. Okumura, Mie University; 

M. Emoto, T. Toyota, National Institute for Fusion 

Science. 

Computational fluid dynamics (CFD) and theoretical analysis are 

conducted for fundamental designs of the circulation of liquid 

nitrogen (LN2) as a coolant in SC power cables. 

The pressure drop of bellows and corrugate inner pipes may be higher 

than that of straight pipes. Since surface areas of the bellows and 

corrugate pipes are wider than that of the straight pipes, the heat 

leakage of the straight pipes by radiation will be lower those of the 

bellows and corrugate pipes. Therefore, our design of DC-SC power 

transmission line uses the straight pipe for one HTS cable. 

CFD analysis is powerful to obtain the optimum design of the straight 

pipe, however this can’t be applied for long distance pipes because of 

the limit of computer memories and CPU power. Hence, theoretical 

analysis is also important to fix the design of the longer pipes. In this 

paper, we describe the method of CFD and the analytical model to get 

the optimum designs of the longer pipe. 

This work is supported in part by “University-Industry Research 

Project for Private Universities matching fund” by subsidy from 

MEXT, Japan, 2005-2009. 

C1-D Pulse Tube Cryocoolers (Non- 

Aerospace) 

C1-D-01 Single-stage Coaxial GM type Pulse Tube 

Refrigerators Below 20K 

B.Y. Du, L.W. Yang, J.H. Cai, J.T. Liang, Technical 

Institute of Physics and Chemistry, Chinese Academic 

of Sciences. 

Pulse tube refrigerators have demonstrated many advantages with 

respect to temperature stability, vibration, reliability and lifetime 

among cryocoolers. Double-inlet type pulse tube refrigerators are 

popular in GM type pulse tube refrigerators. 

Experiments and numerical simulations are carried on to investigate 

the double-inlet characters GM type pulse tube refrigerators. Two 

parallel-placed needle valves with opposite flow direction named 

double-valve configuration, instead of single double-inlet valve, are 

used in our experiment to reduce the DC flow.The lowest cold end 

temperature of 18K has been obtained while the refrigerator is driven 

by compressor of 6 kW power. Moreover, a numerical model is made 

to analyze the characters of double-inlet refrigerators. The simulation 

results show the temperature field and velocity field of pulse tube with 

and without the double-inlet. 

C1-D-02 Numerical simulation of Double-inlet GM type 

Pulse Tube Refrigerators 

B.Y. Du, L.W. Yang, J.H. Cai, J.T. Liang, Technical 

Institute of Physics and Chemistry, Chinese Academic 


Pulse tube refrigerators have demonstrated many advantages with 

respect to temperature stability, vibration, reliability and lifetime 

among cryocoolers. Double-inlet type pulse tube refrigerators are 

popular in GM type pulse tube refrigerators. The mass flow rate 

through the double-inlet is caused by the pressure drop through the 

regenerator, which improves the performance of pulse tube 

refrigerator. However, single double-inlet valve may introduce DC 

flow in refrigerator, which deteriorates the performance of pulse tube 

refrigerator, so it is crucial to control the DC flow. 

Experiments and numerical simulations are carried on to investigate 

the double-inlet characters GM type pulse tube refrigerators. Two 

parallel-placed needle valves with opposite flow direction named 

double-valve configuration, instead of single double-inlet valve, are 

used in our experiment to reduce the DC flow.The lowest cold end 

temperature of 18K has been obtained while the refrigerator is driven 

by compressor of 6 kW power. Moreover, a numerical model is made 

to analyze the characters of double-inlet refrigerators. The simulation 

results show the temperature field and velocity field of pulse tube with 

and without the double-inlet. 



Double-inlet is a key factor for a double-inlet type pulse tube 

refrigerators. It is important to understand the characters of doubleinlet. 

Deep research on characters of double-inlet will be very helpful 

to reveal the mechanics of pulse tube refrigerator. 

This work is supported by Natural Sciences Foundation of China 

(50206025). 

C1-D-03 Experimental Studies on a Two-Stage Pulse 

Tube Cryocooler Reaching 3.3 K 

S. Kasthurirengan, G. Srinivasa, G.S. Karthik, Centre 

for Cryogenic Technology, Dept. of Physics, Indian 

Institute of Science; K.P. Ramesh, Dept. of Physics, 

Indian Institute of Science; K.A. Shafi, TKM College 

of Engineering, Kollam, Kerala, India. 

A two stage Pulse Tube Cryocooler is designed and fabricated, which 

reaches no load temperatures of 3.3 K in the second stage and ~60 K 

in the first stage respectively. The system provides a refrigeration 

power of ~ 250mW at 5 K in the second stage. Stainless steel meshes 

(size 200) and lead (Pb) granules are used as first stage regenerator 

materials and combinations of Pb with Er3Ni or Pb with HoCu2 are 

used as second stage regenerator materials. The system operates at 1.8 

Hz using an indigenous rotary valve along with a 6 kW water-cooled 

Helium compressor. 

Studies conducted by varying the dimensions of Pulse Tubes and 

regenerators for the first and second stages show that pulse tube 

dimensions are more critical to the performance of the Cryocooler 

than those of the regenerators. Experimental studies show that the 

optimum volume ratio of Pb to Er3Ni or HoCu2 (in the second stage) 

should be ~ 3:2 for the best performance of the Cryocooler. Further, 

systems with HoCu2 performed better than those with Er3Ni. Pulse 

Tube Cryocoolers performed better when operated with anti-parallel 

double inlet valves than when operated with other DC flow 

arrangements. 

Theoretical analysis of the above two-stage Pulse Tube Cryocooler 

system has been carried out using a simple isothermal model. The 

experimentally measured cooling powers are in close agreement with 

the theoretical predictions. 

Financial support for the study has come from the Council of 

Scientific and Industrial Research, New Delhi, India. 

C1-D-04 A buffered rotary valve system of GM-type 

pulse tube refrigerator 

G. Hwang, J. Jung, S. Jeong, KAIST. 

In a GM or a GM-type PTR (Pulse Tube Refrigerator), considerable 

amount of helium flow is produced during the pressure transition 

periods from high to low values or vice versa. In a conventional rotary 

valve system, however, this kind of helium in- and out-flow which are 

supplied directly from the helium compressor does not contribute to 

the actual refrigeration power. We devised a buffered rotary valve 

system in order to reduce such an unnecessary helium flow from the 

compressor. In a buffered rotary valve system, pressurizing and 

depressurizing flow is not solely supplied by the compressor but also 

provided by a buffer volume. Theoretically, half of the transition flow 

can be alleviated in the compressor with a single buffer. The aim of 

the buffered rotary valve system is to use a compressor more 

effectively and make the expansion process in PTR more efficient. In 

this paper, the buffered rotary valve system is introduced at the first 

time, fully described with simple thermodynamic analysis, and also 

investigated experimentally to show its performance increase. 

This research was supported by a grant from Center for Applied 

Superconductivity Technology of the 21st Century Frontier R&D 

Program funded by the Ministry of Science and Technology, Republic 

of Korea. 

C1-D-05 An experimental study of the G-M type two- 

Stage Pulse Tube Cryocooler for cryopump 

S.J. Park, Y.J. Hong, H.B. Kim, Korea Institute of 

Machinery & Materials; S.J. Lee, Hyunmin 

Laboratory. 

The pulse tube cryocooler, which has no moving parts at its cold 

section, is attractive in obtaining higher reliability, simpler 

construction, and lower vibration than any other small cryocoolers. 

Korea Institute of Machinery & Materials(KIMM) has developed G- 

M type and Stirling type pulse tube cryocooler since 1992. The 

developments in KIMM on the pulse tube cryocooler systems have 

focused primarily on refrigeration capacity, efficiency and 

performance reliability as well as mechanical reliability. The purpose 

of this study is to provide reliable, efficient and long life cryocoolers 

for cooling systems in cryopump and other applications. The G-M 

type two-stage pulse tube cryocooler consists of a helium compressor, 

a pulse tube, regenerator, orifice, double inlet valve, a buffer 

(reservoir) volume and vacuum chamber. This paper describes the 

two-stage pulse tube cryocoolers designed for cooling arrays of the 

cryopump and their performance characteristics. 

C1-D-06 Optimization of two stage pulse tube 

refrigerator for the integrated current lead system 

R. Maekawa, S. Takami, A. Okada, T. Mito, National 

Institute for Fusion Science; Y. Matsubara, KEK; M. 

Konno, Fuji Electric Systems Co.; A. Tomioka, Fuji 

Electric Advanced Technology Co.; T. Imayoshi, H. 

Hayashi, Kyusyu Electric Power Co.. 

The integrated current lead system, consists of a copper lead, a High 

Temperature Superconductor and two stage pulse tube refrigerator, 

has been developed for Superconducting Magnetic Energy Storage 

(SMES) system. A two-stage pulse tube refrigerator, series connected 

arrangement, was designed to satisfy the requirements for the 

integrated current lead system. Operation of the first stage 

refrigerator is four-valve method, while the second stage utilizes a 

double inlet method. This arrangement ensures the compactness of 

the current lead system. Refrigeration process of two-stage pulse tube 

refrigerator has been investigated to validate the conceptual design 

and finalize the current lead system development. 

This work is supported by the NEDO under the contract of 

"Superconducting Power Network Control Technology Development" 

and by NIFS under ULAA114. The authors wish to acknowlege H. 

Ohkubo at Suzuki Shokan Co. for his support. 

C1-D-07 Damping of Intrinsic Temperature Oscillations 

in a 4 K Pulse Tube Cooler 

by Means of Rare Earth Plates 

G. Thummes, L.M. Qiu, M. Dietrich, K. Allweins, 

University of Giessen. 

Regenerative cryocoolers, such as GM-coolers and pulse tube coolers, 

show oscillations of the refrigeration temperature that result from the 

periodic expansion of the working fluid (helium). In case of cryogenfree 

operation of sensitive superconducting devices the temperature 

oscillations can be rather disturbing because of the associated 

variation of the critical current and gap voltage. The oscillations can 

be damped by increasing the thermal mass attached to the cold end of 

the cooler. For cooling near 4 K it is impractical to employ normal 

metals for this purpose as in this case the specific heat of helium 

greatly exceeds that of normal metals. Here we report on the damping 

of temperature oscillations by making use of the high specific heat of 

rare-earth alloys, such as ErNi. Tests were performed on two types of 

in-house made 4 K pulse tube coolers with input powers of 6 kW and 

1.7 kW. The damping is accomplished by ErNi-plates of different 

thickness that were installed between the cold end of the 4 K stage 

and the device mounting platform. E.g., with a 3.6 mm thick ErNiplate 

(mass: 55 g) the temperature oscillation at 3.5 K was reduced by 

a factor of 18 from 90 mK to 5 mK in the 1.7 kW-system. The thermal 

resistance of the plate was 9 K/W, which was sufficiently low to 

successfully operate an AC Josephson voltage standard near 4 K by 

this set-up. 

This work has been supported in part by the German BMBF (FKZ 

13N8410). L.M. Qiu (permanent address: Zhejiang University, 

Hangzhou 310027, P.R. China) thanks the DAAD for a fellowship. 



C1-E Superconducting RF Cavities and 

Cryosystems - I 

C1-E-01 Superconducting Radiofrequency Separator 

Cryogenic System 

A. Ageyev, S. Kozub, A. Orlov, S. Zintchenko, Institute 

for High Energy Physics. 

Institute for High Energy Physics (Protvino, Russia) develops new 

channel of U-70 accelerator. Important part of the channel is RF 

superconducting kaon separator which consists of two niobium 

cavities cooled by superfluid helium at 1.8 K. The cryogenic and 

vacuum system description, test results and planned improvements are 

presented. 

C1-E-02 Compact He II cooling system for 

superconducting cavities 

T. Kuriyama, M. Takahashi, N. Kakutani, T. Ota, K. 

Nakayama, Toshiba Corporation; E. Kako, S. 

Noguchi, M. Ono, K. Saito, S. Shishido, Y. Yamazaki, 

KEK, High Energy Accelerator Research 

Organization. 

The paper describes a compact He II cooling system for 

superconducting cavities. The cooling system is mainly comprised of 

a vacuum vessel, 77K liquid nitrogen bath, a He I bath, a He II bath, a 

evacuation pump, a single stage GM cryocooler for 77K bath and a 4 

K GM cryocooler. Superfluid helium is generated and refilled in the 

HeII bath via a heat exchanger and a JT valve by operating the 

evacuation pump. The refrigeration capacity attained was more than 

10 W @ 1.8 K. The cooling system was connected with a single 

cavity vessel and a circulation loop. A superconducting cavity was 

immersed in the vessel. He II was supplied to the cavity vessel from 

the cooling system and evaporated helium gas was returned to it. The 

high electric field was successfully obtained by the superconducting 

cavity operation. 

C1-E-03 Superconducting Radio-Frequency Modules 

Test Facility Operating Experience 

A. Klebaner, R. Bossert, B. DeGraff, C. Darve, A. 

Martinez, L. Pei, W. Soyars, J.C. Theilacker, 

Fermilab. 

Fermilab is heavily engaged and making strong technical 

contributions to the superconducting radio-frequency research and 

development program (SCRF R&D). Four major SCRF test areas are 

being constructed to enable vertical and horizontal cavity testing, as 

well as cryomodule testing. The existing Fermilab cryogenic 

infrastructure has been modified to service Fermilab SCRF R&D 

needs. The first stage of the project has been successfully completed, 

which allows for distribution of cryogens for a single cavity 

cryomodule using the existing Cryogenic Test Facility (CTF) that 

houses three Tevatron satellite refrigerators. The cooling capacity 

available for cryomodule testing at MDB results from the liquefaction 

capacity of CTF cryogenic system. The cryogenic system for a single 

9-cell cryomodule is currently operational. The paper describes the 

status, challenges and operational experience of the initial phase of the 

project. 

*Work supported by the U.S. Department of Energy under contract 

No. DE-AC02-76CHO3000. 

C1-E-04 Microwave response of a cylindrical cavity made 

of bulk MgB2 superconductor 

A. Agliolo Gallitto, G. Bonsignore, M. Bonura, M. Li 

Vigni, University of Palermo, Dipartimento di Scienze 

Fisiche e Astronomiche; G. Giunchi, EDISON SpA R 

& D; Yu. A. Nefyodiv, Institute of Solid State Physics, 

RAS. 

We report on the microwave properties of a resonant cylindrical 

cavity made of bulk MgB2 superconductor, produced by Reactive 

Liquid Mg Infiltration process [1]. The resonant cavity has been 

characterized by measuring its frequency response in the range 5 – 13 

GHz by an hp-8719D Network Analyzer. Among the various modes, 

two of them have shown the highest quality factors; they correspond 

to the TE_011 and TE_012 modes. At room temperature, and with the 

cavity filled by helium gas, the resonant frequencies of these modes 

are f_011 = 9.79 GHz and f_012 = 11.54 GHz. At T=4.2 K, without 

liquid helium inside the cavity, the unloaded quality factors are Q_011 

= 220000 and Q_012 = 190000; both maintain values of the order of 

100000 up to about 30 K and decrease by a factor 20 when the 

superconductor goes to the normal state (at T=38.5 K) [2]. The values 

of the surface resistance at 9.79 GHz as a function of the temperature, 

deduced from the Q measurements, agree quite well with those 

independently measured, by the hot-finger cavity perturbation at 9.4 

GHz, in a small sample of MgB2 extracted from the same specimen 

from which the cavity has been obtained. 

[1] G. Giunchi, G. Ripamonti, T. Cavallin, E. Bassani, Cryogenics 46 

(2006) 237. 

[2] G. Giunchi, A. Agliolo Gallitto, G. Bonsignore, M. Bonura, M. Li 

Vigni, submitted to Supercond. Sci.Technol., cond-mat/0612159. 

C1-E-05 Simulation of the impact of the Kapitza 

resistance at grain-grain boundaries on Niobium 

superconducting cavities 

J. Amrit, Q. Li, LIMSI - CNRS. 

We examine the influence of the Kapitza resistance at grain-grain 

boundaries on the thermal behaviour of superconducting cavities 

made of polycrystalline Niobium. Calculations are performed for 

different grain sizes. The results indicate that a non-uniform size 

distribution of grains leads to an inhomogeneous temperature 

repartition in the cavity walls. Also, the importance of the grain-grain 

Kapitza resistance, compared to the Kapitza resistance at the 

niobium/helium interface, is revealed for the first time. 

C1-F Thermal Insulation Systems - I 

C1-F-01 Design Tool for Cryogenic Thermal Insulation 

Systems 

J.A. Demko, Oak Ridge National Laboratory; J.E. 

Fesmire, NASA Kennedy Space Center; S.D. 

Augustynowicz, Sierra Lobo Inc.. 

Thermal isolation of low temperature systems from ambient is a 

constant issue faced by practitioners of cryogenics. For energyefficient 

systems and processes to be realized, thermal insulation must 

be considered as an integrated system, not merely an add-on element. 

A design tool to determine the performance of insulation systems for 

comparative trade-off studies of different available material options 

was developed. The approach is to apply thermal analysis to standard 

shapes (plane walls, cylinders, spheres) that are relatively simple to 

characterize with a one dimensional analytical or numerical model. 

The user describes the system hot and cold boundary geometry and 

the operating environment. Basic outputs such as heat load and 

temperature profiles are determined. The user can select from a builtin 

insulation material database or input user defined materials. 

Existing information combined with the new experimental thermal 

conductivity data produced by the Cryogenics Test Laboratory for 

cryogenic and vacuum environments, including high vacuum, soft 

vacuum, and no vacuum, is planned for incorporation. Materials 

include multilayer insulation, aerogel blankets, aerogel bulk-fill, 

foams, powders, composites, and other constructions. Results of the 

design tool are provided for some sample applications. 

Funding was provided by the NASA Space Operations Mission 

Directorate under the Internal Research and Development project 

Technologies to Increase Reliability of Thermal Insulation Systems. 



C1-F-02 Cryogenic Thermal Performance Testing of 

Bulk-Fill and Aerogel Insulation Materials 

B.E. Scholtens, J.E. Fesmire, J.P. Sass, NASA KSC; 

S.D. Augustynowicz, K.W. Heckle, Sierra Lobo, Inc. 

The research testing and demonstration of new bulk-fill materials for 

cryogenic thermal insulation systems was performed by the 

Cryogenics Test Laboratory at NASA Kennedy Space Center. 

Thermal conductivity testing under actual-use cryogenic conditions is 

a key to understanding the total system performance encompassing 

engineering, economics, and materials factors. A number of bulk fill 

insulation materials, including aerogel beads, glass bubbles, and 

perlite powder, were tested using a new cylindrical cryostat. Boundary 

temperatures for the liquid nitrogen boil-off method were typically 

293 K and 77 K. Tests were performed as a function of vacuum 

pressure level from high vacuum to no vacuum conditions. Results 

are compared with other complementary test methods in the range of 

300 K to 10 K. Various testing techniques are shown to be required to 

obtain a complete understanding of the operating performance of a 

material and to establish a basis for answers to design engineering 

questions. 

C1-F-03 Multilauer Insulation for Atlas 

S. Kozub, K. Polkovnikov, A. Hartchenko, Institute for 

High Energy Physics. 

Multilayer insulation consists of aluminized mylar and mylar cloth 

spacer for ATLAS (LHC) was manufactured and tested at Institute for 

High Energy Physics (Protvino, Russia). The paper presents 

description of facility for the multilayer insulation test as well as 

results of gassing in vacuum rate and heat leakage measurements for 

the insulation. 

C1-F-04 Testing of a Vacuum Insulated Flexible Line 

With Flowing Liquid Nitrogen During the Loss of 

Insulating Vacuum 

J.A. Demko, M.J. Gouge, R.C. Duckworth, Oak 

Ridge National Laboratory; M. Roden, Southwire 

Co.. 

Long length vacuum insulated lines are used to carry flowing liquid 

nitrogen in several high temperature superconducting cable projects. 

An important, but rare, failure scenario is the abrupt or catastrophic 

loss of the thermal insulating vacuum producing a rapid increase in 

heat transfer to the liquid nitrogen stream. In this investigation, a 

vacuum superinsulated 3 inch by 5 inch NPS is subjected to an abrupt 

loss of vacuum in order to measure the response of a flowing liquid 

nitrogen stream and the temperature response of the cryostat. The 

measured outlet stream temperature has a slight peak shortly after the 

loss of vacuum incident and drops to a steady state value. The heat 

loads measured before and after the vacuum loss event are reported. 

Some measurements of the temperatures in the multi-layer 

superinsulation are also discussed. 

Research sponsored by the U.S. Department of Energy - Office of 

Electricity Delivery and Energy Reliability, Superconductivity 

Program for Electric Power Systems under contract DE-AC05- 

00OR22725 with Oak Ridge National Laboratory, managed and 

operated by UT-Battelle, LLC. 

C1-F-05 Radiation heat measurement on thermally 

isolated double-pipe for DC superconducting power 

transmission 

M. Hamabe, S. Yamaguchi, Chubu University; A. 

Ninomiya, Seikei University; Y. Ishiguro, S. Kusaka, 

JFE Steel Corporation. 

Multilayer insulation (MLI) is a strong tool to reduce the radiation 

heat and is widely used for the cryogenic systems. However, the use 

of the MLI leads to a huge increase of the surface area in vacuum; it 

takes extremely long time to reach a satisfactory vacuum for the 

thermal isolation, or the nitrogen gas flushing is needed several times. 

We have started the experiment by using the test bench of the DC 

superconducting (DC-SC) power cable in Chubu University. Since the 

DC-SC power cable is free from the AC losses, the acceptable 

radiation heat can be higher for this cable than the AC-SC power 

cable. Therefore, we are studying the possibility of the radiation shield 

without the MLI. The vacuum pumping process and the radiation heat 

are measured for the thermally isolated double-pipes (of the same size 

as those for the DC-SC PT cable) with the various surfaces. While the 

radiation heat for the liquid-nitrogen-filled double-pipe with the MLI 

radiation shield was 1/100 of that with the bare stainless steel surface, 

the reachable vacuum pressure with the MLI was 10 times poorer than 

that with the bare surface. We will also discuss a novel and 

convenient radiation shielding method for the different surface 

processes in this work. 

C1-F-06 Low temperature heat transfer properties of 

electrical insulation for the Next European Dipole 

J. Polinski, B. Baudouy, CEA Saclay; S. Canfer, G. 

Ellwood, RAL. 

The heat transfer properties of the electrical multilayer insulations of 

the Next European dipole has been tested under various conditions at 

low temperature. The electrical insulation is made of E-glass fibre 

with a plain weave and RAL epoxy system 227 (DGEBF epoxy resin 

and DETD aromatic hardener). The samples have been tested in 

superfluid helium where heat is applied perpendicularly to the fibres 

between 1.6 K to 2.1 K and their thermal conductivity, longitudinal to 

the fibres, had been also measured at low temperature below 77 K. 

This work was supported in part by the European Community– 

Research Infrastructure Activity under the FP6 “Structuring the 

European Research Area” program (CARE, contract number RII3- 

CT-2003-506395). 

C1-F-07 Flexible Aerogel Composites for Cryogenic 

Insulation 

R. Trifu, R. Begag, G. Gould, O. Evans, S. White, 

Aspen Aerogels, Inc.. 

Low-density, flexible aerogel composites offer a variety of 

performance advantages over other insulation materials for cryogenic 

insulation applications, particularly Multi-Layer Insulation (MLI). 

These advantages include reduced weight, increased durability, lower 

total costs, and dramatic improvements in lead-times required for 

fabrication / installation of the insulation with equal thermal 

performance. Additionally, large error bars often associated with the 

thermal modeling of MLI can be eliminated with the use of aerogel 

composites. These low density aerogel composites have been found 

to be compatible with sensitive space sensors. Outgassing data along 

with encapsulation concepts for the aerogel composites will be 

discussed. A ‘higher’ density aerogel composite for insulating liquid 

oxygen transfer lines and storage containers will also be presented. 



Tuesday, 07/17/07 Oral 

10:30am - 12:00pm 

C1-G He II Transfer and Fluid Mechanics - I 

C1-G-01 PIV Measurement Result of Superfluid He II 

Thermal Counterflow Jet 

M. Murakami, T. Takakoshi, University of Tsukuba. 

We have attempted the application of PIV (Particle Image 

Velocimetry) technique to the measurement of superfluid helium 

thermo-fluid dynamic phenomena. Micro solid H-D particles were 

used as tracer particles that are nearly neutrally buoyant in superfluid 

helium. We have succeeded in the production of neutrally buoyant H- 

D particles with adequate particle size distribution and number density 

in He II for PIV measurements in the temperature range between 1.80 

K and 2.17 K that is wider than that in our previous PIV experiment. 

The thermal counter flow jet that flows out from the straight jet nozzle 

into an open quiescent He II space is measured by applying the PIV 

technique with the image data analysis based on the cross-correlation 

method. Two-dimensional velocity field on a plane including the jet 

axis is obtained in the downstream jet region including the vicinity of 

the jet nozzle exit. The data are averaged to extract the mean velocity 

distribution. We obtained some systematic data on the spatial 

variation of the distribution of the average axial velocity component, 

and on the temperature dependence of the axial velocity near the jet 

exit in that temperature range. The dependency of the data on the 

temperature and the heat flux is compared with both the theoretical 

prediction and the previous LDV (Laser Doppler Velocimeter) 

measurement data. 

C1-G-02 PIV measurements of He II flow in a horizontal 

channel 

T. Xu, S.W. Van Sciver, National High Magnetic Field 

Laboratory, Florida State University. 

He II single phase forced flow and thermal counterflow in a horizontal 

channel have been investigated using the Particle Image Velocimetry 

(PIV) technique. The experimental channel used in this research is 3.5 

meter long with a 20 mm X 20 mm square shape cross-section. We 

use solid H2, D2 and solid H2/D2 particles as tracers for the PIV 

measurements. The tracer particles are generated during the 

experiment by freezing the injected seeding gas in the channel. We 

measure the velocity field of He II in both flows. The results are 

compared with theoretical calculations. The effect of the different type 

of particles on the PIV measurements is also discussed in this paper. 

This work is supported by U.S. Department of Energy-Division of 

High Energy Physics. 

C1-G-03 Visualization study of phase transition caused 

by heating of He II in two-dimensional narrow channel 

S. Takada, M. Murakami, Tsukuba University; N. 

Kimura, KEK; H. Kobayashi, Institute of Quantum 

Science, Nihon University. 

A visualization study was carried out by shadowgraph method for a 

number of phase transitions of He II in a two-dimensional narrow 

channel. The experiment was focused on the visual observation of 

phase transition interface of three types. The first is the vapor-liquid 

(He II) interface indicating the onset of film boiling, of which 

propagation could be observed. The second is the He I- He II 

interface, which is very important to recognize the onset of film 

boiling in subcooled He II. The third is the superheated He I- He II 

interface that indicate occurrence of superheated He I- He II interface 

in the superheated state. The detailed observation of this interface 

would be of great help to reveal the dynamic behavior of it that was 

originally discovered from the temperature measurement by H. 

Kobayashi et. al..[1] 

These visualization experiments were conducted using the Claudettype 

cryostat equipped with two optical windows. The visualization 

system was set based on the shadowgraph method. The behavior of 

phase transition interface was observed using a high speed camera. 

We succeed in taking pictures to indicate the appearance of these 

interfaces with aid of image processing technique to enhance S/N 

ratio. 

[1]: Kobayashi H., Yagi K., Takeda K., Fukaya M., Takahashi M. 

and Ashimori T., Proceedings of ICEC 21 (2007), in press 

The present study was carried out partly by the support of the Grandin 

Aid for Scientific Research from the Japan Society for the 

Promotion of Science. 

C1-G-04 Investigation of transient heat transfer in porous 

media in He II 

H. Allain, B. Baudouy, CEA. 

An experimental set up was designed and built in order to study the 

transient heat transfer regimes of superfluid helium through porous 

media. Tests have been performed on different porous media samples, 

which differ by their thickness, their porosity and their average pore 

size diameter. Temperature has been measured across porous media 

from 1.4 K to 2.1 K in saturated superfluid helium. A step heat flux is 

applied for a given bath temperature and the evolution of temperature 

has been measured across the porous media. Results, representing the 

evolution of the temperature in time for a given heat flux, are 

presented and analyzed by using the energy equation for He II in the 

Gorter-Mellink regime. The effects of the properties of porous media 

are also discussed. 

C1-G-06 Experimental tests of the HVBK equations for 

He II 

H.A. SNYDER, University of Colorado at Boulder. 

We generally accept the HVBK equations as those governing the 

motion of He II. The simplest test of these equations, that involves all 

the terms, is the calculation of the onset of instability of rotating 

Couette flow. Linear perturbation methods and difference methods 

using the full nonlinear equations show that the critical Reynold`s 

number, and the wave number of the instability rapidly approach zero 

as the temperature drops below the lambda point. For a narrow gap 

the wave length becomes longer than practical test instruments at 

about 2.07 K. As the gap increases, theory concludes that the 

approach to zero is more rapid. The experimental data agree well 

with the calculations near the lambda point when the test apparatus is 

sufficiently long. However, several investigators report unexplained 

breaks in the slope of torque data and second sound attenuation data at 

much lower temperatures. Nonlinear analysis predicts that the onset 

is not strongly affected by the aspect ratio for a narrow gap. I 

reanalyzed my second sound attenuation data for a wide gap at 1.63 K 

in detail in an attempt to understand the discrepancy. We resolve the 

identification of the various second sound modes by a direct acoustic 

approach. We report the slopes of each mode. We suggest several 

causes of the breaks in slope and test them against the data. 

C1-H Regenerator Performance 

C1-H-01 Calculated Regenerator Performance at 4 K 

with Helium-4 and Helium-3 

R. Radebaugh, Y. Huang, A. O`Gallagher, J. Gary, 

National Institute of Standards and Technology. 

For regenerative cryocoolers operating with the cold end near 4 K the 

helium-4 working fluid no longer behaves as an ideal gas. As a result, 

the losses in the regenerator, given by the time-averaged enthalpy 

flux, are increased and are strong functions of the operating pressure 

and temperature. Helium-3, with its lower boiling point, behaves 

somewhat closer to an ideal gas in this low temperature range and can 

reduce the losses in 4 K regenerators. An analytical model is used to 

find the fluid properties that strongly influence the regenerator losses 

as well as the gross refrigeration power. Numerical modeling of 

regenerator performance at 4 K with helium-3 working fluid has now 

been made possible by the incorporation of the thermodynamic and 

transport properties of helium-3 into the latest NIST regenerator 

model, known as REGEN3.3. With this model we show how the use 

of helium-3 in place of helium-4 can improve the performance of 4 K 

regenerative cryocoolers. The effects of operating pressure, warmend 

temperature, and frequency on regenerators with helium-4 and 

helium-3 are investigated and compared. The results are used to find 

optimum operating conditions. The frequency range investigated 

varies from 1 Hz to 30 Hz, with particular emphasis on the higher 

frequencies. The majority of the studies are for a regenerator matrix 

of packed spheres. The effect of the matrix heat capacity is also 

investigated. 

Funding from the Office of Naval Research is acknowledged 



C1-H-02 Application of Novel Regenerator Material 

Within a Coaxial Two-Stage Pulse Tube Refrigerator 

T. Koettig, F. Richter, R. Nawrodt, M. Thuerk, P. 

Seidel, Friedrich-Schiller-University Jena. 

We have developed a lead-based regenerator material which is 

suitable for working temperatures below 20 K. This material can be 

used as a substitute for the state of the art materials used today within 

very low-temperature regenerators. This high efficient regenerator 

matrix combines technological advantages with the possibility to vary 

the thermodynamic and flow characteristics over a wide range, 

continuously. Hence, our self-made electroplated screen material is 

compared with standard regenerator materials (commercially available 

woven screens and packed spheres). The gap between matrix 

porosities of standard screens around 0.65 and the porosity of packed 

spheres with 0.38 is stepwise investigated regarding the pressure drop 

and heat transfer characteristic. The design parameters and the 

influencing variables to optimise the regenerator performance will be 

discussed. The utility of the shop-made lead coated regenerator 

material is demonstrated in a coaxial two-staged pulse tube 

refrigerator with working temperatures below 7 K. 

C1-H-03 The Impact of Uncertainties Associated with 

Regenerator Closure Parameters on the Predicted 

Performance of Pulse Tube and Stirling Cryocoolers 

J.S. Cha, W.M. Clearman, S.M. Ghiaasiaan, P.V. 

Desai, G.W. Woodruff School of Mechanical 

Engineering Georgia Institute of Technology. 

Recent investigations have shown that computational fluid dynamics 

(CFD) techniques can be used for modeling the entire pulse tube 

(PTR) and Stirling cryocooler systems. However, the results of CFD 

simulations can be trusted only if they are based on correct closure 

relations. The hydrodynamic and heat transfer parameters associated 

with regenerators are among the most important and poorlyunderstood 

closure relations for these cryocooler systems. In this 

investigation the impact of uncertainties associated with flow 

resistance parameters, as well as solid-fluid heat transfer coefficients, 

on the performance of PTR and Stirling cryocoolers is examined using 

CFD simulations. This objective is achieved by performing 

simulations where reference PTR and Stirling cryocooler systems 

operating in steady-periodic conditions are modeled in their entirety. 

The effects of uncertainties in the regenerator closure parameters on 

the cryocoolers performance parameters, as well as their key local 

hydrodynamic and heat transport processes, are quantified by the 

parametric variation of the aforementioned regenerator closure 

parameters. 

C1-H-04 New Thermoacoustic Model, New Measurement 

Principle and Experimental Results of Flowing and Heat 

Transfer Characteristics of Regenerator 

Y.Y. Chen, Graduate University of Chinese Academy 

of Sciences; E.C. Luo, Technical Institute of Physics 

and Chemistry, CAS; W. Dai, Technical Institute of 

Physics and Chemistry,CAS. 

Regenerators play key role in oscillating-flow cryocoolers or 

thermoacoustic heat engine systems. However, their flowing and heat 

transfer mechanism is still not well understood. In this paper, the 

authors present a new methodology for studying flowing and heat 

transfer characteristics of the oscillating flow regenerator. First we 

will present a new thermoacoustic model for oscillating-flow 

regenerator. In the model, the local flow and heat transfer 

performance of the regenerator can be characterized by its equivalent 

thermoacoustic viscous and thermal functions, and a dimensionless 

local averaged temperature gradient. Then, we present a simple 

acoustical method and experimental system to get the functions. Here, 

pressure measurements and velocity measurements by hot wire 

anemometry were performed with different screen-packed 

regenerators to obtain the two functions. With the two measured 

functions, local flowing friction factor and heat transfer coefficient 

within the regenerators where mean temperature gradient exists can be 

predicted. Finally, local flowing and heat transfer coefficients are 

summarized with several dimensionless groups for general and 

convenient using. 

This work was supported by the Natural Science Foundation of 

China(Grant No.50625620) 

C1-H-05 Longitudinal Hydraulic Resistance Parameters 

of Cryocooler and Stirling Regenerators in Periodic Flow 

J.S. Cha, S.M. Ghiaasiaan, P.V. Desai, G.W. 

Woodruff School of Mechanical Engineering Georgia 

Institute of Technology. 

The results of an on going research program aimed at the 

measurement and correlation of anisotropic hydrodynamic parameters 

of widely-used cryocooler regenerator fillers are presented. The 

hydrodynamic parameters associated with longitudinal steadyperiodic 

flow are addressed in this paper. An experimental apparatus 

consisting of a cylindrical test section packed with regenerator fillers 

is used for the measurement of axial permeability and Forchheimer 

coefficients, with pure helium as the working fluid.The regenerator 

fillers that are tested include stainless steel 400-mesh screens with 

69.2% and 62% porosity, stainless steel 325-mesh screens with 69.2% 

and 62% porosity, stainless steel 400-mesh sintered filler with 62% 

porosity, and stainless steel sintered foam metal with 56% porosity. 

The test section is connected to a Stirling type compressor on one end 

and to a constant volume chamber on the other end. The 

instrumentation includes piezoelectric pressure transducers at both 

ends of the regenerator. For each filler material, time histories of local 

pressures at both ends of the regenerator are measured under steady 

periodic conditions over a wide range of oscillation frequencies. A 

CFD assisted methodology is then used for the analysis and 

interpretation of the measured data. The permeability and 

Forchheimer parameter values obtained in this way are correlated in 

terms of the relevant dimensionless parameters. 

C1-H-06 A new correlation of friction factor for 

oscillating flow regenerator operating at high frequencies 

Y.L. Ju, Q.Q. Sheng, Shanghai Jiaotong University. 

Regenerator plays an important role on the performance of low-power 

cryocoolers, in particular at high operating frequencies. The ability to 

accurately predict the pressure drop and phase shift across the 

regenerator is directly related to the cooling capacity and efficiency of 

a cryocooler. Many works have revealed that the friction factors under 

unidirectional steady flow conditions are unsuccessful in predicting 

the flow characteristics of regenerators typically operating at 

oscillating flow and pulsating pressure conditions. Recent researches 

have been conducted, using both theoretical analyses and 

experimental measurements, either to correlate the conventional 

friction factor by introducing additional parameters or to develop new 

flow models to overcome the shortcoming of the steady-flow friction 

factor. However, validation and application of these results for 

cryocooler regenerators are still questionable because of the complex 

and randomly oriented matrix geometry of actual regenerators. In this 

paper, we will first summary typical experimental results and 

correlations on the friction factor of regenerators for different sizes of 

packed woven screens, at different frequencies, at room and cryogenic 

temperatures. The comparison of those friction factor data will then be 

presented to clarify the reason for their difference. Finally, a new 

correlation of friction factor for oscillating flow regenerator, in terms 

of two non-dimensional parameters, will be presented. 



C1-I Cryogenic Cooling of High Temperature 

Superconducting Devices 

C1-I-01 High Temperature Superconducting Degaussing 

- Cooling two HTS coils with one cryocooler for the 

Littoral Combat Ship 

B.K. Fitzpatrick, J.T. Kephart, E.M. Golda, NAVSEA 

NSWCCD Philadelphia. 

The concept of creating a high temperature superconducting 

degaussing system has previously been studied by the Navy and 

shown to provide significant weight savings over conventional copper 

based degaussing systems. Modeling efforts have shown that in a 

HTS Degaussing System for the Littoral Combat Ship the dominant 

costs are cryocoolers. In an effort to minimize the number of 

cryocoolers a two coil demonstrator cooled off of one cryocooler has 

been constructed at NAVSEA Philadelphia. The demonstration 

consists of two 72 foot long sections of flexible cryostat that are 

electrically isolated but connected in series through two junction 

boxes for gas flow. Within each cryostat section, 12 turns of HTS 

represent a vertical and horizontal degaussing coil. Use of Helium as 

the working fluid reduces safety impacts and allows higher current 

density in the HTS conductor. Testing of this two coil degaussing 

system includes characterizing the helium flow for a matrix of 

conditions including helium charge pressure and circulating fan speed. 

The results of helium flow characterization are presented in this paper. 

C1-I-02 Thermal Fatigue Test Apparatus for Large 

Superconducting Coils 

J.T. Kephart, B.K. Fitzpatrick, NAVSEA NSWCCD 

Philadelphia; J.C. Chen, Rowan University. 

The Navy has a continued interest in the development of High 

Temperature Superconducting (HTS) to provide power dense, 

efficient propulsion and electrical power generation. These machines 

have large HTS rotor coils that will undergo many thermal cycles 

during the life of the ship. Thermally fatiguing tests for large coils is 

necessary to understand any degradation and life issues that could 

arise. NSWCCD has sponsored Rowan University to design and build 

a device that will assist in the thermal fatigue testing of 

superconducting coils. It was designed to be autonomous with 

programmable cool down and warm-up rates and varying 

temperatures from ambient temperature down to 77K. A typical test 

would include thermally cycling a coil a specified number of times, 

then performing a critical current test on the coil and repeating the test 

cycle as many times as desired. This paper introduces the thermal 

cycling test setup and presents preliminary calibration data. 

C1-I-03 Flow Cooling of Superconducting Magnets for 

Spacecraft Applications 

A.J. Dietz, W.E. Audette, M.D. Barton, Creare Inc.; 

W.S. Marshall, C.M. Rey, Tai-Yang Research 

Corporation; D.S. Winter, A.J. Petro, , NASA 

Johnson Space Center. 

The development and testing of a flow cooling system for hightemperature 

superconducting (HTS) magnets is described. The system 

includes a turbo-Brayton cryocooler, a magnet thermal interface, and 

a magnet thermal isolation and support system. The target application 

is the Variable Specific Impulse Magnetoplasma Rocket (VASIMR). 

Turbo-Brayton coolers are well suited to such spacecraft applications, 

as they are compact, modular, lightweight, and efficient, with long 

maintenance-free lifetimes. Furthermore, the technology scales well 

to high-cooling capacities. The feasibility of using turbo-Brayton 

coolers in this application was proven in a design exercise in which 

existing cooler designs were scaled to provide cooling for the magnet 

sets required by 200 kW and 1 MW VASIMR engines. The 

performance of the concepts for the thermal interface and the thermal 

isolation and support system were measured in separate laboratory 

tests with a demonstration system built about a representative HTS 

magnet. Cooling for these tests was provided by a flow cooling loop 

comprising a compressor, recuperator and GM cryocooler, with the 

flow pressure, temperature, and mass flow rate selected to effectively 

simulate the turbo-Brayton operating condition. During system 

testing, the magnet was cooled below its design operating temperature 

of 35 K, and good thermal uniformity (


C1-J Pumps and Compressors 

C1-J-01 Pressure Oscillator Losses at High Frequency 

and High Pressure 

P.E. Bradley, M.A. Lewis, R. Radebaugh, National 

Institute of Standards and Technology; A. Veprik, 

Ricor Ltd, Cryogenic Vacuum Systems. 

High frequencies show potential for reducing the size of both the 

pressure oscillator and cold head for a given cooling power while 

leading to a faster cool-down. Previously, we made comparisons of 

pressure oscillator efficiency employing a total loss method of 

subtracting internal thermodynamic losses from the PV power at the 

piston face for frequencies up to 70 Hz with mean pressures up to 2.5 

MPa for a load optimized for around 45 Hz. In this paper we present 

similar comparisons for high frequency operation up to 120 Hz and 

high mean pressure up to 3.5 MPa for an appropriately optimized 

load. Both small and large pressure oscillators from 4 cm3 to 25 cm3 

are evaluated for high frequency and high pressure operation. We 

discuss pressure and flow losses for the high frequency (120 Hz) and 

high pressure (3.5 MPa) operation compared with 30 to 60 Hz 

frequency and 2.0 to 2.5 MPa pressure operation. Pressure ratios 

ranged from 1.0 to 1.3. The overall compressor efficiency, the 

delivered PV power to a load divided by the electrical input power to 

the compressor is determined for the high frequency and high pressure 

operation as well. 

C1-J-02 Screw Compressor Characteristics for Helium 

Refrigeration Systems 

P.N. Knudsen, V. Ganni, Jefferson Lab. 

The oil injected screw compressors have practically replaced all other 

types of compressors in modern helium refrigeration systems due to 

their large displacement capacity, minimal vibration, reliability and 

capability of handling helium`s high heat of compression. 

At the present state of compressor system designs, half the input 

energy is lost in the compression system. Therefore it is important to 

understand the isothermal and volumetric efficiencies of these 

machines to help properly design these compression systems. This 

presentation summarizes three separate tests that have been conducted 

on Sullair compressors at the Superconducting Super-Collider 

Laboratory (SSCL) in 1993, Howden compressors at Jefferson Lab 

(JLab) in 2006 and Howden compressors at the Spallation Neutron 

Source (SNS) in 2006. Although the compressor pressure ratio and 

built-in volume ratio are the primary parameters affecting the 

efficiencies of the screw compressor proper, it is evident from these 

tests that the compressor skid design also strongly influences the 

overall efficiencies and performance of the compression system. This 

work is part of an ongoing task at JLab to understand the theoretical 

basis for these efficiencies and their loss mechanisms, as well as to 

implement practical solutions. 

C1-J-03 Designing Liquid Cryogenic Systems for Use 

with Centrifugal Pumps 

J.E. Dillard, W.D. Batton P.E., J.A. Busby Ph.D., J.W. 

Shull, M.R. Anderson, Barber-Nichols Inc. 

A cryogenic system is a collection of interdependent components 

working together; therefore, proper system performance is dependent 

upon an understanding of each component’s relationship with other 

components in the system. This paper examines the relationship 

between centrifugal pumps and other components in liquid cryogenic 

systems during cool down and steady state operation. 

Two common problems which affect liquid cryogenic systems are 

cavitation and cryogen vaporation; both can significantly decrease 

mass flow and adversely effect overall system performance. However, 

a system-based, rather than a component-based, design philosophy 

can help avoid these problems. Additionally, cool down and steady 

state operation are two equally important system modes. Excessively 

tight design margins based exclusively on steady state operational 

requirements can compromise a system’s ability to cool itself to its 

operating temperature. 

C1-J-04 Experience with dry running vacuum pumps in 

helium service 

R. Arztmann, Linde Kryotechnik AG. 

A process vacuum system for helium using dry running vacuum 

pumps only was shop tested and installed in a refrigeration plant to 

serve cavities operating at 2K for a cryogenic storage ring. 

The paper explains the joint development steps of Busch AG and 

Linde Kryotechnik AG to use dry running vacuum pumps for helium 

service at ambient temperature. A roots type booster pump followed 

by a non lube rotary screw pump provides very good performance in a 

helium vacuum pump system. Variable frequency drives on both 

pumps allow to adjust the pump characteristics to a wide range of 

operating parameters. Operation without friction of sealing elements 

in the compression space also of the screw pump promises extended 

maintenance intervals and virtually no wear on the rotors. The current 

plant operation at Max Plank Institute in Heidelberg, Germany 

Laboratory will provide additional experience for further applications. 

C1-J-05 Thermal Design of a Superconducting Bearing 

with a Magnetic Journal at Room Temperature. 

X. Granados, Q Lloberas, ICMAB-CSIC; J López, R 

Maynou, CEIB. 

Interaction between permanent magnets and superconducting pellets 

provides a stable and durable way for bearing in both thrust and axial 

bearing. The axial symmetry of the magnetic field, and that of the 

inertia axis, allow achieving non-friction rotating coupling thus 

improving reliability and a simplification of the bearing design. The 

cooling requirement of the superconductors is a main concern because 

the life and the losses of the bearing are essentially the life and 

efficiency of the cooling system. In this work we present the thermal 

design of a passive thrust bearing with a room temperature magnetic 

journal and a plane superconducting stator. In this paper, we discuss 

the main points for optimization of the gap thermal isolation in order 

to achieve the minimum losses-stiffness ratio. 

Tuesday, 07/17/07 Poster 

1:30pm - 3:00pm 

C1-K Low Temperature Superconducting 

Magnet Systems - I 

C1-K-01 Leak-tight welding experience from the 

Industrial assembly of the LHC cryostats at CERN. 

V. Parma, N. Bourcey, P. Campos, A. Mongelluzzo, A. 

Poncet, CERN; P. Limon, FNAL; G. Musso, SERCO. 

The assembly of the approximately 1700 LHC ring cryostats at 

CERN involved extensive welding of cryogenic lines and vacuum 

vessels. More than 6 km of welding requiring leak tightness to a rate 

better than 1.10-9 mbar.l.s-1 on stainless steel and aluminium piping 

and envelopes was made, essentially by manual welding but also 

making use of orbital welding machines. In order to ensure the 

fulfillment of safety regulations of pressure vessels and to comply 

with the leak-tightness requirements of the vacuum systems of the 

machine, welds were executed according to high qualification 

standards and following a severe quality assurance plan. Leak 

detection by He mass spectrometry was extensively used. Neon leak 

detection was used successfully to locate leaks in the presence of 

helium backgrounds. The use of SF6 as a tracer gas with a sniffer was 

also tried. 

This paper presents the quality assurance strategy adopted for welds 

and leak detection. It presents the statistics of non-conformities on 

welds and leaks detected throughout the entire production and the 

advances in the use of alternative leak detection methods in an 

industrial environment. 



C1-K-03 Heat Exchanger Design Studies for an LHC 

Inner Triplet Upgrade 

R. J. Rabehl, Y. Huang, Fermi National Accelerator 

Laboratory. 

A luminosity upgrade of the CERN Large Hadron Collider (LHC) is 

planned to coincide with the expected end of life of the existing inner 

triplet quadrupole magnets. The upgraded inner triplet will have 

much larger heat loads to be removed from the magnets by the 

cryogenics system. Within the framework of a design temperature 

profile, a number of design studies have been completed to investigate 

the required characteristics of a heat exchanger to transfer this heat 

from the pressurized He II bath to the saturated He II system. This 

paper presents limitations of the existing bayonet heat exchanger, 

required attributes of a heat exchanger external to the magnet cold 

mass, and required attributes of a heat exchanger internal to the 

magnet cold mass. 

C1-K-04 High Intensity Neutrino Source 

Superconducting Solenoid Cryostat Design 

T.M. Page, T.H. Nicol, S. Feher, I. Terechkine, J. 

Tompkins, Fermi National Accelerator Laboratory. 

Fermi National Accelerator Laboratory (FNAL) is involved in the 

development of a 100 MeV superconducting linac. This linac is part 

of the High Intensity Neutrino Source (HINS) R&D Program. The 

initial beam acceleration in the front end section of the linac is 

achieved using room temperature spoke cavities, each of which is 

combined with a superconducting focusing solenoid. These solenoid 

magnets are cooled with liquid helium at 4.5K, operate at 250 A and 

have a maximum magnetic field strength of 7.5 T. The solenoid 

cryostat will house the helium vessel, suspension system, thermal 

shield, multilayer insulation, power leads, instrumentation, a vacuum 

vessel and cryogenic distribution lines. This paper discusses the 

requirements and detailed design of these superconducting solenoid 

cryostats. 

C1-K-06 Development of new cooling system using 

GM/JT cryocoolers for the SKS magnet 

K. Aoki, T. Haruyama, Y. Makida, O. Araoka, K. 

Kasami, T. Takahashi, T. Nagae, Y. Kakiguchi, KEK; 

T. Orikasa, T. Kuriyama, TOSHIBA. 

The SKS (Superconducting Kaon Spectrometer) worked in the K6 

beamline of the KEK 12-GeV PS for the study of nuclear physics 

from 1991 until 2006. After shutdown of the KEK 12-GeV PS, KEK 

and JAEA are constructing new accelerator facility J-PARC (Japan 

Proton Accelerator Research Complex) as a joint project. The SKS 

magnet, which is a large sector type superconducting magnet, is 

intended to be improved and used in the new Hadron Hall of the J- 

PARC. In our schedule, the magnet will be disassembled and 

improved from 2007 to 2008, and reassembled in early 2009. The new 

nuclear physics experiments at the J-PARC will start in the middle of 

2009. The main change is to adopt a new cooling method using 

several GM/JT cryocoolers instead of an old 300W cold box. Recent 

improvement of the refrigeration power of the GM/JT cryocooler 

made this coolig method possible. Adopting this compact cooling 

methods also brings new possibilities to the spectrometer. One 

example is an easy maintenance. In this paper, we explain our project 

and describe our first result of the heat leak measurement test of a 

model port using a GM/JT cryocooler. 

C1-L Low Temperature Superconducting 

Magnet Systems - II 

C1-L-01 Characterization of the ENEA new concept joint 

for Cable-In-Conduit-Conductors 

Aldo Di Zenobio, Luigi Affinito, Ugo Besi Vetrella, 

Sandro Chiarelli, Antonio della Corte, Chiarasole 

Fiamozzi Zignani, Ferruccio Maierna, Giuseppe 

Messina, Luigi Muzzi, Matteo Napolitano, Luigi 

Reccia, Stefano Rueca, Simonetta Turtù, Rosario 

Viola, ENEA. 

In large superconducting magnets, joints connecting different 

conductor unit lengths are unavoidable and represent one of the 

main causes of dissipation due to their resistive behavior, as well as a 

key element in determining the distribution of transport current within 

the conductor section. A joint of new concept in shaking-hands 

configuration has been designed and patented by ENEA. It is based on 

the idea of cutting the last-but-one cabling stages of the two 

conductors to be joined at different lengths in a complementary way, 

matching the two ends. As a result, the cable original shape and size is 

maintained over the joint length. A detailed description of the joint 

design has been presented elsewhere. In this paper we describe the 

results of its experimental characterization, using both Nb3Sn and 

NbTi Cable-in-Conduit Conductors: some samples have been 

prepared using spare lengths of the new European Dipole conductor 

and some with an ITER sub-size NbTi cable. For all of them, we 

performed DC resistance measurements at sufficiently high current 

and AC losses characterization, both in straight or bent configurations. 

Moreover an interesting trial has been made, manufacturing a joint 

sample without removing the Ni coating from NbTi strand 

surfaces, in order to investigate its impact on the joint resistance. 

C1-L-02 Freely Oriented Portable Superconducting 

Magnet 

E.N. Schmierer, C. Prenger, D. Hill, B. Charles, Los 

Alamos National Laboratory; G. Laughon, R. 

Efferson, American Magnetics Incorporated. 

A high-field LTS solenoidal magnet was developed that can be 

operated in any orientation relative to gravity and is portable. The 

design consists of several features that make it unique; 1) bulk liquid 

cryogen storage occurs in a separate dewar rather than as part of the 

magnet assembly, which allows for single-person transport due to its 

low weight and size, 2) vapor generated pressure circulates liquid 

cryogen to and from the magnet with flexible transfer lines allowing 

operation in any orientation, and 3) composite, low-conducting 

structural members are used to suspend the magnet and shield layers 

within the vacuum vessel that provide a robust low heat loss design. 

Cooling is provided to the magnet through fluid channels that are in 

thermal contact with the magnet. The overall design is presented and 

analysis for cooldown time and weight are discussed as well. 

C1-L-03 Helium-Liquefaction by a Cryocooler in Closed- 

Loop Cooling System for 21 T FT-ICR Magnets 

Y.S. Choi, KBSI-NHMFL RCC; T.A. Painter, 

NHMFL; D.L. Kim, B.S. Lee, H.S. Yang, KBSI. 

An experiment of helium liquefaction using a two-stage pulse tube 

cryocooler is performed. The main objective of this study is to 

confirm the feasibility of our recently proposed cryogenic design for a 

21 T FT-ICR superconducting magnet system by closed-loop cooling 

concept without any replenishment of cryogen. Since the cold surface 

of a cryocooler is very limited, a cylindrical copper fin is thermally 

anchored to the first and second stage coldheads in order to extend the 

available heat transfer surface. A heat exchanger tube is attached on 

the outer surface of each cylindrical fin and heat exchange occurs 

between tube and helium gas which is passing through the tube. The 

temperature distributions along the copper cylinder and heat 

exchanger are measured in steady state and compared with the 

numerical analysis. The effect of mass flow rate, inlet pressure of 

helium, and cooling capacity of cryocooler on the liquefaction rate is 

also investigated. 



C1-L-04 Development of Cooling System for Cryogenic 

Preamplifier in FT-ICR Ion Trap 

Y.S. Choi, KBSI-NHMFL RCC; D.L. Kim, M.C. Choi, 

H.S. Kim, J.S. Yoo, KBSI; T.A. Painter, NHMFL. 

The cooling system of cryogenic preamplifier is designed and 

fabricated for Fourier Transform Ion Cyclotron Resonance (FT-ICR) 

ion trap. A cryogenic preamplifier consisted of non-magnetic 

materials is thermally contact to the cooling medium which is passing 

through the flange maintaining high vacuum in the ion cell. At the 

other end, the cooling medium is thermally anchored to the coldhead 

of cryocooler or liquid helium reservoir. This cryogenic preamplifier 

is installed in 7 Tesla FT-ICR system. The temperature distribution 

along the cooling medium is measured for cool-down and steady state, 

and compared with the result of numerical analysis. The reduction of 

thermal noise is discussed in term of the temperature. The detail of 

flange for cooling medium withstanding severe thermal, mechanical 

and electrical operation is also described. 

C1-L-05 Developmnet and Production of a Low Noise 

LHe4 Cryostat for use in High Magnetic Pulsed Fields 

P.F. Ruminer, C.H. Mielke, J.B. Betts, National High 

Magnetic Field Lab, LANL. 

Pulsed Field Magnets, up to 100 Tesla, provide a valuable 

environment for materials studies. 

The Magnets at NHMFL-LANL operate at 77K, have a 15mm bore 

and are powered by a 1.6MJ cap bank with pulses at up to 10KV at 

16KA and a rise time of approximately 12mS. Sample data is taken in 

the mVolt range, 10 orders of magnitude less than the power in the 

magnet. Our He3 Fridges provide a 300mK sample space diameter of 

just over 6mm. Background noise produced by sample movement in 

the field, eddy current heating, field perturbation and temperature 

fluctuations can make these measurements very difficult. Conductive 

materials in close proximity to the magnet greatly add to this 

background noise. We have developed a new LHe4 cryostat that is 

quite robust and has drastically reduced the mass of material in this 

critical area, creating a much quieter and more stable data collection 

environment. In addition, we have made repairing of the tail section, 

in the case of Magnet failure, less expensive, faster and requiring less 

effort. The intention was also to increase the hold time in order to 

reduce He4 costs and increase the available data collection time each 

day. Since the NHMFL-LANL is a User Facility, this is all very 

important due to the often limited time our Users are able to spend at 

our Facility. In this poster I will present Cryostat design, noise data, 

temperature stability and LHe4 hold time data compared to previous 

designs. 

C1-L-06 Fiber Bragg Grating Sensors for Measuring 

Temperature and Strain Simultaneously at Cryogenic 

Temperature 

R. Rajinikumar, Inst. of Technial Physics, 

Forschungszentrum Karlsruhe, Dept. of Mechanical 

Engg., Indian Inst. of Technology, Sensor System 

Technology, Univ. of Applied Sciences; M. Suesser, 

Institute of Technial Physics, Forschungszentrum 

Karlsruhe; K.G. Narayankhedkar, M.D. Atrey, 

Department of Mechanical Engineering, Indian 

Institute of Technology; G. Krieg, Sensor System 

Technology, University of Applied Sciences. 

We study the feasibility of employing fiber Bragg gratings (FBG) for 

measuring thermodynamics parameters of super conducting coils. The 

distributions of mechanical stress and temperature inside the coil are 

important for an optimized design. Standard sensors with electrical 

connections like resistance thermometer and strain gauges cannot be 

placed inside the coil. So it is impossible to access local stress and 

temperature data. The superimposed dual wavelength metallic 

recoated Bragg gratings, fabricated in one fiber at same location are 

better suited for this purpose. Coil temperature and stress will vary the 

gratings periods which can be read out with a tunable laser. The 

spectral position of the reflections may be correlated with the spatial 

position of the gratings, and the shift of the gratings’ maximum 

reflection indicates the change of the gratings’ period. This, in turn 

measures temperature and stress. The Simultaneous temperature and 

strain measurement response of an Indium metal coated FBG sensor is 

reported in this paper. 

C1-M Aerospace Cryogenics 

C1-M-01 Development of Cryogenic Loop Heat Pipe 

R. Karunanithi, S. Jacob, D.S. Nadig, U. Behera, A.K. 

Sahoo, Centre for Cryogenic Technology, IISc.; 

G.S.V.L. Narasimham, Department of Mechanical 

Engineering, IISc; D. Kumar, Thermal Systems 

Group, ISAC, ISRO.. 

The loop heat pipes (LHP) are different from conventional heat pipes, 

in that, the wick structure is required only in the evaporator section. 

Consequently, smooth wall tubing can be employed in the 

construction of the vapour and liquid lines, which avoid the 

significant liquid-flow losses. As it is confined to such a small length, 

very small pore size wicks can be used in applications with high 

thermal transport requirements and/or where the heat must be 

transported over a long distance against gravity. The diode nature of 

LHP is intrinsic. The design of a Cryogenic Loop Heat Pipes (CLHP) 

has to take care of supercritical nature of the working fluid at room 

temperature and take care of the self-priming of the heat pipe action at 

start-up. The research and development of a CLHP is presented in the 

paper. A mathematical modeling and FORTRAN program to solve 

and determine the parameters for various boundary conditions has 

been developed. The CLHP is designed to transfer 5W heat at 70K 

using nitrogen as working fluid. It will be a self priming type device 

which can operate against gravity with evaporator above the 

condenser as well as under microgravity condition. Its performance 

will be tested by coupling it with a home made pulse tube refrigerator. 

The design fabrication and performance of a cryogenic heat pipe with 

s.s. wick at the evaporator for a heat transfer of 5 W at 70 K will be 

described in the paper. 

C1-M-02 Thermal Management Options for Cryogenic 

Propellant Tanks and Other Large Structures 

J.R. Feller, L.J. Salerno, NASA-ARC; A. Kashani, 

B.P.M Helvensteijn, Atlas Scientific. 

Various thermal control options, both passive and active, enabling 

long-term storage of cryogenic propellants in zero boil-off (ZBO) or 

reduced boil-off (RBO) states, will be discussed. The primary focus 

will be on methods of active heat transfer from propellant tank walls 

or thermal shields, via enthalpy flow in large-scale distributed cooling 

networks, to a remotely located cryocooler cold head. While 

ZBO/RBO propellant storage is the only application explicitly 

addressed, the methods described would allow efficient cryogenic 

temperature control of other large or remote structures (e.g., sensor 

arrays). In addition to in-space design concepts and modeling results, 

the capabilities and potential applications of an experimental 

apparatus, constructed specifically to investigate the behavior of 

distributed cooling networks, will be described. 

C1-M-03 Large-Scale Cryogenic Testing of Launch 

Vehicle Ground Systems at Kennedy Space Center 

E.W. Ernst, D.E. Taylor, J.P. Sass, NASA KSC; D.A. 

Lobmeyer, S.J. Sojourner, ASRC Aerospace; W.H. 

Hatfield, D.A. Rewinkel, Sierra Lobo, Inc.. 

The development of a new launch vehicle to support NASA’s future 

exploration plans requires significant redesign and upgrade of 

Kennedy Space Center’s (KSC) launch pad and ground support 

equipment systems. In many cases, specialized test equipment and 

systems will be required to certify the function of the new system 

designs under simulated operational conditions, including propellant 

loading. This paper provides an overview of the cryogenic test 

infrastructure that is in place at KSC to conduct development and 

qualification testing that ranges from the component level to the 

integrated-system level. An overview of the major cryogenic test 

facilities will be provided, along with a detailed explanation of the 

technology focus area for each facility. 



C1-M-04 Three Dimensional Transient Heat Transfer 

Modeling of Cryogenic Rocket Engine Thrust Chamber 

B.T. Kuzhiveli, National Institute of Technology 

Calicut; G.K. Kuruvilla, Liquid Propulsion Systems 

Centre ISRO. 

In a cryogenic engine thrust chamber making use of LH2-LOX 

combination, liquid hydrogen is passed through the regenerative 

channels to take care of the high energy combustion resulting out of 

close to three by fourth stoichiometric mixture ratio combustion. 

However the cryogenic cooling results in wide range of temperature 

distribution in the cross section and along the axis of the thrust 

chamber with respect to time and poses serious thermo-structural 

problems. In order to have an unnderstanding of temperature 

distribution, an accurate prediction of heat transfer characteristics for 

the complete spectrum of the thrust chamber with respect to time is 

necessary. The objective of this paper is to present transient thermal 

analysis with three dimensional approach which can provide transient 

temperature distribution along the axis and across the cross section 

during transient and steady state conditions for chill down and hot 

test. A computational model has been developed for the prediction of 

temperature distribution on the thrust chamber which could be suited 

for parametric studies and also for generating an optimum design for 

cryogenic rocket engines to recommend stable operation. 

C1-M-05 Lox Separation Studies Using Cryogenic Vortex 

Tubes 

S. Jacob, P.J. Paul, R. Karunanithi, U. Behera, Indian 

Institute of Science. 

In-flight collection of air, pre-cooling, liquefaction and separation of 

liquid oxygen (LOX) are key technologies for futuristic launch 

vehicles. Vortex tube technology is one of the few promising 

technologies for this application. Significant work has been carried 

out at IISc Bangalore in developing cryogenic vortex tube technology 

for high purity LOX separation. Experimental studies have been 

conducted on temperature separation and LOX separation both for 

straight and conical vortex tubes by varying various parameters. 

Though straight vortex tubes are found to perform better for 

temperature separation, they are not suitable for LOX separation as 

compared to conical vortex tubes. Experiments have been conducted 

to study the influence of supply pressure and inlet temperature for 

conical vortex tubes of L/D of 10, 20, 25 and 30 to achieve high LOX 

purity and separation efficiency. Studies show that it is not possible to 

obtain both high LOX purity and high separation efficiency 

simultaneously in a single vortex tube. However, experimental results 

show that it is possible to achieve both high LOX purity and 

separation efficiency by staging of vortex tubes. LOX purity of 96% 

and separation efficiency of 73.5% has been achieved for second stage 

vortex tube supplied with pre-cooled air having 60% oxygen purity. 

LOX purity has been further increased to 97% by applying controlled 

heating power over liquid oxygen flowing discharge surface of vortex 

tube. 

C1-M-06 Radiation Analysis of anti-Stokes fluorescent 

Cryocooler with Network-Matrix Method 


Calicut ; S. Jacob, Indian Institute of Science 

Bangalore . 

Attaining cooling effect by using laser induced anti-Stokes 

florescence in solids appears to have several advantages over 

conventional mechanical systems and has been the topic of recent 

analysis and experimental work. Using anti-Stokes fluorescence 

phenomenon to remove heat from a glass by pumping it with laser 

light, stands as a pronouncing physical basis for solid state cooling. 

Cryocooling by fluorescence is a feasible solution for obtaining 

compactness and reliability. It has a distinct niche in the family of 

small capacity cryocoolers and is undergoing a revolutionary advance. 

In pursuit of developing laser induced anti-Stokes fluorescent 

cryocooler, it is required to develop numerical tools that support the 

thermal design and therefore a thorough analysis of radiation heat 

transfer mechanism within the cryocooler is necessary. The paper 

presents the details of numerical model developed for the cryocooler 

and the subsequent development of a computer program. The program 

has been used for the understanding of various heat transfer 

mechanisms in particular the radiation heat transfer and is being used 

for thermal design of components for an anti-Stokes fluorescent 

cryocooler. 

The development of optical cryocooler is progressing at the Indian 

Institute of Science (I.I.Sc), Bangalore under the auspices of the 

Defense Research Development Organization (DRDO). The author is 

a consultant for thermal design of the optical cryocooler. 

C1-M-07 Thermal Model for a Mars Instrument with 

Thermo-Electric Cooled Focal Plane: CCD Subsystem 

with Heat Switch 

D.R. Ladner, J.P. Martin, N-Science Corporation. 

The Mineral Identification and Composition Analyzer (MICA) is a 

miniature instrument that employs X-ray scattering and visual 

imaging to determine nondestructively the mineralogy of a rock 

sample in-situ. The CCD subsystem comprises the CCD focal plane, 

the thermoelectric cooler (TEC), the TEC heat sink, a passive heat 

switch, and the subsystem radiator. The TEC is used to hold the CCD 

focal plane at or below 208 K during instrument operation. The 

inclusion of the heat switch and TEC are found to significantly extend 

instrument observation times and to enable schedule flexibility during 

extreme Martian diurnal temperature excursions of atmosphere (175 - 

255 K) and sky (130 - 200 K). The CCD Subsystem Model includes 

all parasitic and dissipative heat sources. The model incorporates logic 

that simulates heat switch operation to provide heat sink cool-down by 

night and isolation by day if a sufficient temperature difference exists 

between the radiator and the sink; the sink must not exceed 258 K. 

Model parameter variation allows the instrument designer to optimize 

the subsystem thermal parameters to minimize input power to the 

TEC and maximize instrument observation periods. This paper 

extends previous results to include all combinations of heat switch 

status, TEC status, and ambient environmental conditions. Recent 

imaging and X-ray diffraction and fluorescence test results of the 

MICA prototype instrument are discussed. 

C1-M-08 Novel Optical Cooler with Thermoelectrically 

Cooled Radiation Shield 

S. Jacob, R. Karunanithi, K.S. Sangunni, K.T. 

Aruldasan, M. Venkateshan, Indian Institute of 

Science; B.T. Kuzhiveli, VICET; R. Srinivasan, Raman 

Research Institute. 

Optical cooling using laser induced anti-Stokes fluorescence in 

appropriate solid materials is a potential candidate for future cooler 

applications. They are characterized by positive features such as no 

vibration, no moving part, low mass, compact and maintenance free 

long life operation. The paper discusses the efforts made to develop 

an optical cooler by developing the appropriate materials technology 

of ZBLANP fluoride glass and also the development of the optical 

cooler cryostat. The novel feature of the design is the incorporation of 

a radiation shield cooled by a thermoelectric cooler, which enables to 

shield the optical cooler element from ambient radiation and also to 

mitigate the heating effect of the leaked fluorescent emission from 

dielectric coated cooler element surfaces. A nodal network thermal 

analysis has been carried out to optimize the thermal performance of 

the cooler. The paper describes design of the cryostat and the 

experimental work carried out. 

C1-M-09 Development of a cryogen-free continuous ADR 

system for micro-gravity experiments. 

K. Takahashi, H. Nakagome, Chiba University; K. 

Kamiya, T. Numazawa, National Institute for 

Materials Science; P. Shirron, D. Wegel, 

NASA/GSFC. 

It has been widely recognized that ultra low-temperature environment 

is vital foundation to implement micro-gravity missions such as basic 

science and X-ray astronomy. In particular, TES(Transition Edge 

Sensor) type X-ray microcalorimeters, being planned for future 

science satellite missions in JAXA, NASA and ESA, requires a 

temperature of 100mK or less. Added to these, study on formation of 

solid helium facet as an example of basic science under micro-gravity 

also needs 100mK environment. For ground-based experiments, 

dilution refrigerators make use of the gravity, it is difficult for them to 

implement under micro-gravity environment. On this point, the ADR 

has advantage since it is independent of the gravity. In this study, we 

will report development of a cryogen-free continuous ADR originally 

developed by NASA/GSFC and its cooling application for airborne 

micro-gravity experiment planned by NIMS, GSFC and JAXA. 



C1-M-10 Development of a Cryogenic Gate Valve with 

Robust Sealing 

W.H. Hatfield, Sierra Lobo, Inc.; J.P. Sass, NASA 

KSC. 

A soft-seat cryogenic gate valve has been designed, fabricated, and 

demonstrated by the Cryogenics Test Laboratory at the Kennedy 

Space Center (KSC), featuring a robust sealing technology and a high 

Cv flow characteristic. The robust seat design incorporates a novel 

retracting seat-retaining disk to prevent soft-seat abrasive wear and 

damage on the valve body hard seat. Advanced materials were 

incorporated into the design, including porous sponge 

polytetrafluoroethylene (PTFE) for the seat material and titanium 

nitride coating for the 316 stainless-steel surfaces that are subject to 

wearing or galling. The valve is suitable for applications from 

ambient temperature down to liquid nitrogen temperature (77 K), with 

a seat leakage rate of less than 1 sccm per inch of valve diameter. The 

very low seat leakage, throttling capability, and high Cv flow 

characteristic of the valve make it suitable for block valve applications 

on standard to very large cryogenic storage tanks. 

C1-M-11 Atmospheric Pressure Effects on Cryogenic 

Storage Tank Boiloff 

J.P. Sass, C.R. Fortier, NASA KSC. 

The Cryogenics Test Laboratory at the Kennedy Space Center 

routinely uses cryostat test hardware to evaluate comparative and 

absolute thermal conductivities of a wide array of insulation systems. 

The test method is based on measurement of the flow rate of gas 

evolved as a result of evaporative boiloff of a cryogenic liquid. The 

gas flow rate typically stabilizes after a couple of hours to a couple of 

days, depending upon the test setup. The stable flow rate value is then 

used to calculate the thermal conductivity for the insulation system 

being tested. The latest set of identical cryostats, 1000-L spherical 

tanks, exhibited different behavior. On a macro level, the flow rate 

did stabilize after a couple of days; however, the stable flow rate was 

oscillatory, with peak-to-peak amplitude of up to 25% of the nominal 

value and a consistent period. The source of the oscillation has been 

traced to variations in atmospheric pressure caused by atmospheric 

tides similar to oceanic tides. This paper will present analysis of this 

phenomenon, including a calculation that explains why other cryostats 

are not affected by it. 

C1-M-12 Cryocooler Prognostic Health Management 

System 

B. Penswick, Sest, Inc.; A. Shaw, Sest, Inc; C. 

Dodson, T. Roberts, Air Force Research Laboratory. 

High performance sensors are playing an increasingly important role 

in all aspects of all critical DoD missions. There is a family of sensors 

that operate with improved sensitivities if cooled to very low 

(cryogenic) temperatures. For these sensors a healthy and reliable 

mechanical refrigeration system (cryocooler) is required. The ability 

to accurately predict the “health” or remaining useful life of the 

cryocooler has significant benefits from the viewpoint of insuring that 

mission critical functions can be carried out with a high probability of 

success. The proposed paper provides an overview and approaches 

used for the development of a Cryocooler Prognostic Health 

Management System capable of assessing the cryocooler “health” 

from the viewpoint of the level of performance degradation and/or the 

potential for near term failure. Additionally, it quantifies the reliable 

remaining useful life of the cryocooler. While the proposed system is 

focused on the specific application to linear drive cryocoolers, 

especially for DoD, many of the attributes of the system can be 

applied to other specialized system hardware in both commercial and 

U.S. Government agency for situations where it is critical that all 

aspects of the hardware “health” and “remaining useful life” be fully 

understood. Several benefits of the health monitoring system are also 

described in the paper. 

C1-N Large Scale Refrigerators and 

Liquefiers - I 

C1-N-01 The on-site status of the KSTAR helium 

refrigeration system 

H.-S. Chang, D.S. Park, J.J. Joo, K.W. Cho, Y.S. 

Kim, J.S. Bak, National Fusion Research Center; 

H.M. Kim, M.C. Cho, I.K. Kwon, Samsung 

Engineering and Construction Corporation; E. Fauve, 

J.-M. Bernhardt, P. Dauguet, J. Beauvisage, F. 

Andrieu, Air Liquide - Advanced Technologies 

Division; G.M. Gistau Baguer, Consultant - Biviers. 

Since the first “Cryogenic System Design Description” of the KSTAR 

helium refrigeration system (HRS) had been carried out in year 2000, 

many modifications and changes have been applied due to both 

system optimization and improved knowledge of the cold component 

of KSTAR. The present specification of the KSTAR HRS had been 

fixed during the “Design Clarification Meeting”, beginning of year 

2005. Consequent manufacturing of main equipments, such as 

compressor station (C/S), cold box (C/B), and distribution box (D/B) 

was completed by or under the supervision of Air Liquide (AL) DTA 

by the end of 2006. The major components of the C/S are 2 low and 2 

high pressure compressor units and an oil removal system. The 

cooling power of the C/B at 4.5 K equivalent is 9 kW which is 

extracted by 6 AL turbo expanders. The D/B is a valve box housing 

49 cryogenic valves, 2 supercritical helium circulators, 1 cold 

compressor, and 7 heat exchangers immersed in a 4 m3 liquid helium 

storage. The installation and commissioning of the KSTAR HRS is 

planned to be executed in year 2007. 

In this proceeding, we will introduce the on-site installation and 

commissioning status of the KSTAR HRS. In addition, the final 

specification and design features of the HRS and the cooling schemes 

of the KSTAR cold components, which consist of superconducting 

(SC) magnets and corresponding structures, SC bus-lines, current 

leads, and thermal shields, will be presented. 

C1-N-02 The JT60SA Cryoplant Current Design Status 

D. Henry, P. Reynaud, J.-Y. Journeaux, J.-L. 

Maréchal, D. Balaguer, Ch. Roux, Département de 

Recherche sur la Fusion Contrôlée, Association ; F. 

Michel, P. Rousset, Département de Recherche 

Fondamentale sur la Matière Condensée, 

CEA/Grenoble, F-38000 Grenoble France. 

In the framework on the ITER Broader Approach, CEA is carrying 

out the procurement of the Cryogenic System to the JA-EU Satellite 

Tokamak JT60SA, which should be operated in Japan at JAEA, Naka 

since 2014. According to the Conceptual Design Review Report, 

JT60SA is to operate for periods of at least 6 months per years, with 

major shutdown periods in between for maintenance and further 

upgrades installation. For this operation scenario, the cryoplant and 

the cryodistribution have to cope with different heat loads which 

depend on the different JT60SA operating states. The cryoplant 

consists of two 4.5 K refrigerators and one 80 K helium loop coupled 

with an LN2 Pre-Cooler. These cryogenic subsystems have to operate 

simultaneously in order to remove the heat loads from the magnet, 80 

K shields, divertor cryopumps and Pellet Injection System. 

The first part of this study based on the Process Flow Diagram (PFD), 

presents the current design status of the JT60SA cryogenic system. 

The second part is dedicated to the analysis of the cryoplant normal 

operation modes including the regeneration mode of the divertor 

cryopumps. 

Thanks to this analysis, the architecture of the present PFD is 

proposed in order to meet the technical specifications of the cryoplant 

with the JT60SA operation requirements. 



C1-N-03 Performance Study for Cryogenic System at 

NSRRC 

H.H. Tsai, F.Z. Hsiao, H.C. Li, S.H. Chang, W.S. 

Chiou, NSRRC. 

A new cryogenic system was installed on September of the year 2006 

at NSRRC. So far, two superconducting magnets and one 

superconducting cavity for RF are cooled by one 450W liquid Helium 

system which had already been installed on the year 2002. The new 

system is planning to supply the liquid helium to five superconducting 

magnets and being a backup of the first one by transfer valve box. 

This paper presents the variation of parameters which were precooling 

temperature (from 87K to 105K), cold turbine outlet temperature 

(from 10K to 11.5K) and heating power to the stability of operation 

and liquefaction rate. 

C1-N-04 Preliminary Commissioning of Cryogenic 

System of BES III 

Z.G Zong, L. Zhang, L.Q Liu, Technical Institute of 

Physics and Chemistry, Chinese Academy of Sciences; 

S.P. Li, K. He, Institute of High Energy Physics, 

Chinese Academy of Sciences. 

A helium cryogenic system with cooling capacity of 500 W at 4.5 K 

was set up at Institute of High Energy Physics (IHEP), Chinese 

Academy of Sciences, Beijing. This helium refrigerating system is 

dedicated for the cooling of two interaction region quadrupole 

magnets (SCQ) and one detector solenoid magnet (SSM), which are 

the key devices of the upgrade project of Beijing Electron-Positron 

Collider (BEPC II). Commissioning of the cryogenic system with the 

detector magnet and SCQ magnets was carried out. This paper will 

present the overall status and some test results of the superconducting 

devices and cryogenic system during the commissioning. The fact that 

the cryogenic system stood the racket of the quench of SSM indicates 

the system is very robust. 

C1-N-05 Performance of cold compressors in the subcooling 

system for LHD. 

H. Wakisaka, S. Yoshinaga, T. Takahashi, N. Saji, 

Ishikawajima-Harima Heavy Industries Co., Ltd.; T. 

Mito, S. Imagawa, S. Hamaguchi, , National Institute 

for Fusion Science. 

To attempt the improvement of the cryogenic stability of helical coils 

in the Large Helical Device (LHD) of National Institute for Fusion 

Science(NIFS), the cooling system was upgraded with an additional 

pre-cooler. Two-stage cold compressors were adopted for this system 

to decompress the heat exchanger tank to 24 kPa as 3K sub-cooling 

system. The nominal flow rate is 15.9 g/s at the outlet condition of 

120 kPa. The rotor of the compressor is supported by dynamic gas 

bearings and is driven by a variable-frequency motor that is located at 

the ambient temperature. These designs have the advantage of easy to 

maintenance and high reliability as a complete oil-free machine. 80 K 

gas cooled thermal shielding is adopted between the compressor 

impeller operating at 3.0 K and the ambient temperature part to 

decrease heat leak through the casing and shaft. This compressor is 

able to achieve high performance by adopting this structure and a high 

efficiency impeller. These cold compressors we re able to attain the 

nominal specification as the result of performance tests at NIFS. 

C1-N-06 A Theoretical and Practicle Approach on 20K 

Brayton Refrigerator: KHNP WTRF Helium 

Refrigerator 

P. Briend, E. Fauve, Advanced Technology Division - 

Air Liquide. 

The large 20K refrigerators designed for detritiation facilities or cold 

neutron source are commonly helium Brayton cycle machines. 

Beyond the apparently simple process, it is important to underline the 

weight of each component on the cycle efficiency. A thermodynamic 

and exergetic approach is of great help to design the system and 

analyse the deviations in operation. The WTRF/KHNP 30 kW@20K 

Helium Refrigerator that was commissioned in late 2006 illustrates 

the pertinence of this approach. The analysis of the deviation with 

expected results are explained through theoretical thermodynamical 

and exergetic balance. The focus on the main heat exchanger led to 

the right decision of an upgrading modification. The practical on site 

repair of the defaulted HX is illustrated and the final and successful 

performance test of the refrigerator coupled with the deuterium/tritium 

distillation is presented. 

C1-N-07 Numerical simulation of the cryogenic system of 

BEPC II 

Z.G Zong, L.Q Liu, X.L Xiong, L. Zhang, Technical 

Institute of Physics and Chemistry, Chinese Academy 


Cryogenic system of BEPC II with a total capacity of 1.0 kW at 4.5 K 

for cooling superconducting devices is being built at IHEP. Two sets 

of refrigerators with each capacity of 500 W at 4.5 K are adopted. In 

order to prepare for the commissioning of the cryogenic system, the 

refrigeration process was simulated and analyzed numerically. The 

simulation was conducted based on the latest engineering progresses 

and focusing on the steady state operation mode. The simulation 

results, such as the helium mass flow rates and pressure drops over the 

control valves of different cooling channels, thermodynamic 

parameters of each superconducting device, etc., are presented in this 

paper. Under considering the real heat loads, the powers of heaters of 

each device were figured out to realize the nominal operation modes. 

C1-N-08 Dynamic simulation of an helium refrigerator. 

P. Roussel, C. Deschildre, P. Bonnay, J.M. Poncet, F. 

Michel, A. Girard, CEA-Grenoble; A. Barraud, P. 

Briend, Laboratoire d`Automatisme de Grenoble; S.E. 

Sequeira, Air Liquide. 

A dynamic simulation of a large scale existing refrigerator has been 

performed using the industrial software HYSYS. This software is 

mainly used in chemical and refinery industries but is also able to 

cope with cryogenic fluids, as most cryogenic companies already use 

it in steady state mode for design purposes. 

The first goal of our study has been to qualify the dynamic module of 

HYSYS and then to simulate our refrigerator. This refrigerator which 

is the 400W at 1.8K test facility at CEA-Grenoble, comprises all the 

typical equipments of large scale refrigerators: plate fins counter flow 

heat exchangers, centrifugal cold compressors, warm screw 

compressors, helium phase separators and cold turbine. 

This dynamic simulation has helped for process control and regulation 

during normal operation. Existing control loops were taken into 

account in order to simulate the refrigerator behaviour with loads 

variations. 

This paper presents, the model obtained using the HYSYS software 

and the results compared to experimental 



C1-N-09 Understanding dynamic behavior of a large scale 

cryogenic plant 

R. Maekawa, K. Ooba, T. Mito, National Institute for 

Fusion Science; M. Nobutoki, Taiyo Nippon Sanso Co. 

Development of Cryogenic Process REal-time SimulaTor (C-PREST) 

has been finalized to provide a platform to study refrigeration process 

simulation for the entire cryogenic system for the Large Helical 

Device (LHD). To understand dynamic behavior of the LHD 

cryogenic plant, the simulations have been carried out during the 

cooldown operation. Although LHD has three different cooling 

schemes, a pool boiling, a forced-flow supercritical helium cooling 

and a two-phase flow cooling, C-PREST simulates comparable results 

of LHD cooldown process. To validate the versatility of C-PREST, 

the heat pulse(s) were applied to the 20000 liters liquid helium 

reservoir of a helium refrigerator/liquefier. This paper describes 

operations of large cryogenic plant and discusses dynamic behavior of 

helium refrigerator/liquefier under various heat pulse inputs. 

Tuesday, 07/17/07 Oral 

3:00pm - 5:00pm 

C1-O Stirling and Pulse Tube Capabilities 

Overview (Aerospace) 

C1-O-01 Heritage Overview: 20 Years of Commercial 

Cryocooler Production for Space 

A.S. Gibson, J.S. Reed, EADS Astrium Limited. 

Space cryocooler production (formerly BAe and MMS) has spanned 

more than 2 decades. Industrialisation has taken the cryocooler from 

the laboratory to a proven space product. Over this period, Astrium 

have manufactured more than 50 Stirling coolers, 15 of which have 

flown. An historical review with lessons learned is presented. 

Following transfer of the heritage design via Rutherford Appleton 

Laboratory (RAL), manufacturing began at Astrium on the first 80K 

Stirling coolers in 1986, with production of 2 development models (1 

for ESA) and an EM unit. Following successes of Oxford/RAL 

coolers on ISAMS, ATSR-1 and ATSR-2, Astrium built standard 80K 

units for IMG-ADEOS(1996) and HTSSE-II(1997). 23 coolers of this 

type were built in 4 batches. A higher heat lift version (1991) led to 

the standard 50-80K product. These continue to fly in pairs on 

MOPITT(1999), MIPAS(2002), AATSR(2002), INTEGRAL(2002) 

and a military satellite (2004), with a single unit on ODIN(2001). 

Another pair is to be launched in 2007. 

Industrialisation of a 2-stage RAL Stirling cooler design began in 

1990 (ESA funded), to provide cooling from 20-50K. An EM was 

produced, followed by 3 QM units. In 2000, an improved 10K design 

(collaboration with RAL) was built for the US-Air Force Research 

Laboratory yielded a record temperature of 9.4K. Notably, 

development of this design has recently been re-initiated (ESA 

funding). 

Astrium would like to acknowledge funding from ESA for 

industrialisation of cryocoolers. 

C1-O-02 An Overview of the Performance and Maturity 

of Long Life Cryocoolers for Space Applications 

D.G. Curran, S.W. Yuan, The Aerospace Corporation. 

A 2007 survey is made of long life cryocoolers involving Stirling, 

Pulse Tube, reverse Brayton, and Hybrid variants for space 

applications. A number of unit configuration types involving single 

and multi-temperature stages is included. The performance range 

varies from milliwatts of cooling at 4K to 10`s of watts at 150K. The 

objectives for this survey are to provide a hardware summary of 

available units from several U.S. manufacturers including the heritage 

and maturity level suitable for space use in payloads and instruments. 

Listed in the summary are life test and flight hours, environmental test 

levels, size, and electronics controller capabilities as well as load 

curves and specific power as a function of temperature. 

C1-O-03 Endurance Evaluation of Long-Life Space 

Cryocoolers at AFRL- An Update 

J. Sutliff, W. Scheirer, E. Pettyjohn, T. Roberts, 

AFRL/VSSS. 

The Air Force Research Lab (AFRL) in conjunction with various 

defense contractors has developed several long-life cryocooler 

designs. These cooler include the NGST HEC, the Raytheon PSC, the 

Ball 6020, and the Ball 35-60K. They represent different technologies 

including pulse tube and Stirling cycle. The coolers operating times 

range from the NGST HEC which has been running 28,000 hours to 

the TRW 6020 which has been operating for more that 69,000 hours. 

Endurance evaluation attempts to describe the long-life potential of 

these machines with a complete demonstration of these machines 

being 5-10 years of constant operational life in an environment 

designed to simulate the conditions of space. The testing hopes to 

show any wear out, fatigue, or electronic malfunction so that 

cryocoolers will continue to improve their long-life potential. 

Endurance testing also quantifies the performance degradation over 

time to help determine needs of future satellites. Data presented 

indicates that certain degradation patterns exist in these cryogenic 

refrigerators which will pose a challenge for their long term use in 

multi-year missions. 

C1-O-04 Air Liquide Space Pulse Tube Cryocoolers 

T. Trollier, J. Tanchon, J. Buquet, A. Ravex, P. 

Crespi, Air Liquide Advanced Technology Division, 

AL/DTA, Sassenage, France. 

Thanks to important development efforts completed and partial ESA 

funding, AL/DTA is now in position to propose two Pulse Tube 

cooler systems in the 40-80K temperature range for coming Earth 

Observation missions such as MTG, Sentinel 3, etc… The two pulse 

tube coolers thermo-mechanical units are yet qualified against 

environmental constraints. 

In addition to these two Pulse Tube cooler systems, a 20-50K multistage 

low temperature Pulse Tube cooler is currently under 

development for future Scientist Missions such as Xeus, Darwin, etc.. 

The paper presents the current status of each of the three thermomechanical 

units and associated cooler drive electronics. 

C1-O-05 High Performance Pulse Tube Cryocoolers 

J.R. Olson, P. Champagne, E. Roth, B. Evtimov, T.C. 

Nast, Lockheed Martin ATC. 

Lockheed Martin’s Advanced Technology Center (LM-ATC) has 

been developing pulse tube cryocoolers for more than ten years. 

Recent innovations include successful testing of four-stage coldheads, 

no-load temperatures below 4 K, and the recent development of a 

high-efficiency compressor. 

This paper discusses the predicted performance of single and multiple 

stage pulse tube coldheads driven by our new 5 kg “M5Midi” 

compressor, which is capable of 90% efficiency with 200W input 

power, and a maximum input power of 1000W. This compressor 

retains the simplicity of earlier LM-ATC compressors: it has a 

moving magnet and an external electrical coil, minimizing organics in 

the working gas and requiring no electrical penetrations through the 

pressure wall. Motor losses were minimized during design, resulting 

in a simple, easily-manufactured compressor with state-of-the-art 

motor efficiency. 

The predicted cryocooler performance is presented as simple 

formulae, allowing an engineer to include the impact of a highlyoptimized 

cryocooler into a full system analysis. Performance is 

given as a function of the heat rejection temperature and the cold tip 

temperature and cooling load. A discussion of the optimum number 

of coldhead stages will be given. We will also discuss a novel 

configuration where the compressor operates with no heat rejection, 

allowing very flimsy attachment to the satellite so as to minimize 

exported vibration. 



C1-O-06 Ball Aerospace Hybrid Space Cryocoolers 

W. Gully, D.S. Glaister, P. Hendershott, V. Kotsubo, 

E.D. Marquardt, Ball Aerospace & Technologies 

Corp.. 

This paper describes the design, development, testing and 

performance at Ball Aerospace of a long life, hybrid (combination of 

Stirling and Joule-Thomson thermodynamic cycles) space 

cryocoolers. Hybrid coolers are synergistic combination of two 

thermodynamic cycles which combines advantages of each cycle to 

yield overall improved performance. Hybrid cooler performance 

advantages include: 1) load leveling of large heat loads, 2) remote 

cryogenic cooling with very low to negligible induced vibration and 

jitter, 3) very low redundant (off state) cooler penalties, 4) high power 

efficiency, especially at low temperatures, and 5) simplified system 

integration with capability to cross gimbals and no need for thermal 

straps or switches. Ball is currently developing hybrid coolers on 

several programs. The 35 K hybrid cooler provides 2.0 W at 35 K and 

8.5 W at 85 K with an emphasis on load leveling of high transient heat 

loads and remote, low vibration cooling. The 10 K hybrid cooler 

provides 200 mW at 10 K, 700mW at 15 K, and 10.7 W at 85 K with 

an emphasis on power efficiency. In addition, Ball built and tested a 

complete hybrid cooler that met the requirements of the JWST Mid- 

Infrared Instrument (MIRI) cooler including providing 80 mW at 6 K 

and 100 mW at 18 K. 

C1-O-07 Flight Qualified High Capacity Pulse Tube 

Cooler 

C. Jacob, T. Nguyen, J. Raab, Northrop Grumman 

Space Technology. 

The High Capacity Cryocooler Flight Qualified Cryocooler (HCC 

Qual) is designed to provide large capacity cooling at 35K (2.3 Watts) 

and 85 K (14.3 Watts) for space applications which require cold focal 

planes and optics cooling. The HCC Qual is built upon the heritage of 

the High Capacity Cryocooler (HCC) with a coaxial cold head 

configuration. The coaxial configuration minimizes the cooler 

parasitic and offers superior cooler integration. Flight qualification of 

this cryocooler includes thermal performance mapping over a range of 

reject temperatures, launch vibration testing and thermal cycling 

testing. Acceptance test data will be presented. 

C1-O-08 Raytheon Dual-Use Cryocooler Progress 

R.C. Hon, C.S. Kirkconnell, Raytheon Space and 

Airborne Systems. 

Raytheon initiated development of the Dual-Use Cryocooler (DUC) as 

a way of bridging the gap between tactical and space cryocooler 

systems. The goal of the program is to produce a cryocooler system 

with 80% of the typical space system functionality at less than 20% of 

the typical cost. A single-stage pulse tube configuration was selected 

due to its inherently low complexity. The compressor module is a 

dual-opposed, self balanced design, making use of a flexure 

suspension and clearance gap scheme for long operational life. The 

drive electronics is based on a robust tactical design, modified for 

additional functionality and hardened against radiation typical of the 

space environment. 

Development of the DUC system has progressed substantially over 

the past two years, including the design, build and testing of a 

brassboard thermo-mechanical unit (TMU). Demonstrated design 

simplification features and initial test results are presented. 

Significant progress was also made in terms of electronics 

development. Existing tactical assets were modified for use with the 

DUC, including the addition of separate drive circuits for each 

compressor motor. The software was modified to enable features not 

found in typical tactical systems such as first-order active vibration 

cancellation. The brassboard electronics test results are also 

presented. 

C1-P Large Scale Refrigerators and 

Liquefiers - II 

C1-P-01 Large scale helium liquefaction and 

considerations for site services for a plant located in 

Algeria 

P. Froehlich, J.J. Clausen, Linde Kryotechnik AG. 

The large scale liquefaction of helium extracted from natural gas is 

depicted. Based on a block diagram the chain, starting with the 

pipeline downstream of the natural gas plant to the final storage of 

liquid helium is explained. Information will be provided about the 

recent experiences during installation and start-up of a bulk helium 

liquefaction plant located in Skikda, Algeria, including part load 

operation based on a reduced feed gas supply. 

The local working and ambient conditions are described including 

challenging logistic problems like shipping and receiving of parts, 

qualified and semi-qualified subcontractors, basic provisions and tools 

at site, and precautions to sea water and ambient conditions. 

Finally the differences in commissioning (technically and evaluation 

of time and work packages) to a European location and standards will 

be discussed. 

C1-P-02 Status of the refrigeration plant for the 

Electrostatic 

Cryogenic Storage Ring (CSR) at MPI-K in Heidelberg 

R. von Hahn, J. R. Crespo Lopez-Urrutia, H. Fadil, 

M. Grieser, K.-U. Kühnel, M. Lange, D. A. Orlov, R. 

Repnow, T. Sieber, D. Schwalm, J. Ullrich, A. Wolf, 

Max-Planck-Institute for Nuclear Physics; H. Quack, 

Ch. Haberstroh, Technische Universität Dresden; D. 

Zajfman, Weizmann Institute of Science. 

At the Max-Planck-Institute for Nuclear Physics in Heidelberg a nextgeneration 

electrostatic storage ring for atomic and molecular ion 

beams is under construction. In contrast to existing electrostatic 

storage rings our Cryogenic Storage Ring CSR will be cooled down to 

temperatures below 2 K. The low-temperature of the vacuum 

enclosure and all ion optical components decisively reduces the 

influence of the black-body radiation incident onto the stored particles 

such that only the lowest rotational levels of radiatively active 

molecular ions will be occupied. Moreover, due to the excellent 

vacuum of up to 10E-15 mbar highly charged (radioactive) ions or 

antiprotons can be stored with sufficient life times. A concept for the 

cooling of the storage ring has been developed and will soon be tested 

at a prototype with a length of 1/10 of the ring. A commercial 

refrigerator has been largely set up and is now in the commissioning 

phase. In this paper the refrigeration plant and first results of the testoperation 

will be presented. 

C1-P-03 The CERN LHC Refrigeration System 

P. Dauguet, G.M. Gistau-Baguer, P. Briend, B. 

Hilbert, E. Monneret, J.C. Villard, G. Marot, F. 

Delcayre, C. Mantileri, F. Hamber, J.C. Courty, P. 

Hirel, A. Cohu, H. Moussavi, Air Liquide. 

The LHC is the largest particle accelerator in the world. It is a 

superconducting machine over 27 kilometers. Its magnets and cavities 

require helium refrigeration and liquefaction in the temperature range 

1.8 K to 300 K. This is the largest cryogenic system in the world 

regarding the needed cryogenic power : 144 kW equivalent power at 

4.5 K. 

The LHC cryogenic system is composed of 8 x 18 kW at 4.5 K 

refrigerators, 8 x 2.4 kW at 1.8 K refrigerators, 5 main valve boxes, 

more than 27 km of helium tranfer lines and around 300 service 

modules connecting the tranfer line to the magnet and cavity strings. 

Most of these components have been designed, manufactured, 

installed and started up by Air Liquide. Du to the huge size of the 

project, the engineering, construction and commissionning of the 

equipments have lasted for 8 years, from first order of equipments in 

1998 to last commissionning in 2006. Specifications, architecture and 

design of the major components of the LHC Refrigeration System will 

be presented in the present paper. 



C1-P-04 1.8 K refrigeration units for the LHC: conclusion 

of procurement phase and first operational experience 

G. Ferlin, CERN. 

The cooling capacity below 2 K for the superconducting magnets of 

the Large Hadron Collider (LHC) is provided by eight refrigeration 

units of 2400 W at 1.8 K, each of them coupled to a 4.5 K refrigerator. 

After successful testing and acceptance of the pre-series units 

delivered by the two selected vendors, the 2 pre-series units and the 6 

series units were installed in underground cavern at their final 

location. During the last two years, these 8 units were successfully 

tested at their installed capacity in a so-called “capacity check mode”. 

After a brief reminder of the pre-series commissioning tests results, a 

statement of the tests done at installed capacity for the eight units will 

be reported, with emphasis on the reproducibility of the results among 

the four units supplied by each vendor. Conclusion of the procurement 

phase will be drawn with the review of the critical points that have 

been solved. Finally this paper will report on the first operational 

experience of the units during the commissioning of the LHC sectors 

from January 2007 onwards. 

C1-P-05 Design and Manufacturing of the KSTAR 

Tokamak Helium Refrigeration System 

P. Dauguet, P. Briend, I. Abe, E. Fauve, J.M. 

Bernhardt, F. Andrieu, J. Beauvisage, Air Liquide. 

The KSTAR (Korean Superconducting Tokamak Advanced Research) 

project makes intensive use of superconducting magnets operated at 

4.4 K. The cold components of KSTAR require forced flow of 

supercritical helium for magnets and structure, boiling liquid helium 

for current leads, and gaseous helium for thermal shields. A helium 

refrigeration system has been customed design for this project. The 

purpose of this paper is to give a brief overview of the proposed 

cryogenic system. The thermal loads specified to the refrigerator in 

the different operating modes of the KSTAR tokamak will be 

presented. This specification results in the definition of a design mode 

for the refrigerator. The design and construction of the resulting 9 kW 

at 4.5 K Helium Refrigeration System will be presented. 

C1-P-06 Adopted methodology for cool-down of SST-1 

superconducting magnet system: Operational experience 

with the helium refrigerator 

A.K. Sahu, B. Sarkar, P. Panchal, J. Tank, R. 

Bhattacharya, R. Panchal, V.L. Tanna, R. Patel, P. 

Shukla, J.C. Patel, M. Singh, D. Sonara, R. Sharma, R. 

Duggar, Y.C. Saxena, Institute for plasma research. 

The 1.3 kW @ 4.5 K helium refrigerator/liquefier (HRL) has been 

commissioned during year 2003 and since then the HRL is in 

operation for different experiments. The HRL has been operated with 

its different modes as per the functional requirements of the 

experiments. The recent experience of cooling down the magnet 

system (SCMS) of SST-1 with 16 nos. of toroidal field magnets and 9 

nos. of poloidal field magnets has been unique. The cool-down 

experiment of the SCMS has been carried out under physical 

parameter constraints with not so appreciable vacuum inside the 

cryostat as well as uneven temperature distribution on the thermal 

shield at 80 K. Successful attempt has been made to cool the SCMS 

down to 4.5 K. The experience has been unique as new 

thermodynamic balance of the refrigerator had to be adjusted with the 

original boundary condition of the HRL. The enhanced capacity was 

achieved without any additional hardware. The control system of the 

HRL was tuned manually to achieve the stable thermodynamic 

balance, while keeping the turbine operating parameters at optimized 

condition. Extra mass flow rate requirement has been met by 

exploiting the margin available with the compressor station. The paper 

will describe the methodology adopted to modify the capacity of HRL 

with safety precaution and experience of SCMS cool down to 4.5 K. 

The operational experience along with control system of the HRL will 

be discussed. 

C1-P-07 The Relativistic Heavy Ion Collider (RHIC) 

Cryogenic System at Brookhaven National Laboratory: 

Review of the Modifications and Upgrades since 2002 and 

Planned Improvements 

Y.R. Than, J. Tuozzolo , Brookhaven National 

Laboratory; A. Sidi-Yekhlef, V. Ganni, P. Knudsen, D. 

Arenius, Thomas Jefferson National Accelerator 

Facility. 

An ongoing program at Brookhaven National Laboratory consists of 

improving the operational efficiency, reliability and stability of the 

cryogenic system which also resulted in improved beam quality of the 

Relativistic Heavy Ion Collider. 

This paper presents a summary of the changes made over the four 

years and the proposed improvements for the future. The work was 

carried out in several phases by balancing the accelerator’s schedule 

of operation, time required for the modifications and budget 

constraints. The main changes include process control, oil removal, 

piping, elimination of the use of cold compressors, reduction in liquid 

storage, providing additional multi layer insulation on the in-use 

liquid helium reservoirs, and the addition of a load “wet” turbine and 

its associated heat exchangers at the low temperature end of the plant. 

Changes were also made to the cryogenic flow configuration to 

eliminate the use of the liquid helium circulators used to circulate the 

sub-cooled helium through the magnet loops. Future upgrades include 

the resizing of turbines 5 and 6 to increase their efficiencies. 

The paper summarizes the work done to date and the progression of 

improvements after each upgrade phase, starting from the initial 9.3 

MW power usage level to the present 6 MW and the expected level 

below 5 MW after the completion of the remaining improvements. 

C1-P-08 An Overview of the Planned Jefferson Lab 

12GeV 2.1 K Helium Refrigerator 

D. Arenius, J. Creel, K. Dixon, V. Ganni, P. Knudsen, 

A. Sidi-Yekhlef, M. Wright, , Jefferson Laboratory. 

The US Department of Energy (DOE) has placed Jefferson Lab in 

Newport News, Virginia, on a path towards a major upgrade of the 

Continuous Electron Beam Accelerator Facility (CEBAF). In April 

2005, the DOE announced "critical decision zero" (CD-0) for the 

laboratory`s proposal to double the superconducting accelerator`s 

energy from 6 to 12 GeV, add a fourth experimental hall and upgrade 

equipment in the three existing halls. This step established the 

"mission need" and moves the upgrade into a formal project-definition 

phase. In February 2006, the DOE Office of Science approved 

“critical decision 1” (CD-1) status for the project. 

Operating continuously since 1993, the Jefferson Lab’s current 2.1 K 

4600W Central Helium Liquefier (CHL) capacity will be doubled to 

support the upgrade. An overview of the integration of the new 

proposed refrigeration system into CEBAF will be presented inclusive 

of planned work scope, current schedule plans and project status. 

This work is supported under DOE Contract Number DE-AC05- 

06OR-23177 



C1-Q MEMS Coolers 

C1-Q-01 MicroMiniature Refrigeration 

W.A. Little, MMR Technologies, Inc. and Stanford 

University, CA. 

The dramatic growth of industrial cryogenics in the past century has 

overshadowed the need for cryogenics on a smaller scale. Today, 

small scale, MEMS or microminiature refrigerators constitute a small 

part of the field, but one with a unique role to play, often in 

instrumentation. Key attributes of these coolers have proved to be 

their small size of course, very low noise, fast response, and low cost. 

The small size has made possible the integration of the instrument and 

the cooler, thus providing convenience to the end user. The fast 

response and low noise have made possible instruments of unique 

capabilities. We discuss some of these. Opportunities exist for the 

seamless integration of cryogenics in many other products. In order to 

succeed here though, a company needs to be more than a simple 

manufacturer of cryocoolers. Strength is needed in a broad range of 

disciplines, in materials science, electronics, software and 

documentation to name a few. In addition, to offset economies of 

scale, different fabrication technologies have had to be created, and 

others are needed. Some key elements remain to be developed before 

more widespread use of this technology will be seen. Better, low cost, 

manufacturable, miniature heat exchangers and regenerators are 

needed. Development of miniature or sub-miniature compressors to 

power the coolers could herald a new world of cooled devices 

analogous to the revolution created by fractional horsepower electric 

motors in the past fifty years. Opportunities abound! 

C1-Q-02 Heat Transfer Efficiency of Kleemenko Cycle 

heat exchangers. 

W. A. Little, MMR Technologies, Inc. 

During the past decade Kleemenko Cycle coolers have been 

developed to operate at temperatures between 180K and 70K using 

throttle expansion of multi-component refrigerants. They have 

demonstrated remarkable reliability – continuous, maintenance-free 

operation now approaching 100,000hrs, and the simplicity of their 

design and use of low cost components has kept their cost at a small 

fraction of that of any other cryocoolers. They have found markets in 

instrumentation, cooling of X-Ray detectors, in Office liquefiers, 

Automated Test Equipment, and other devices. However, little 

attention has been focused on optimizing the efficiency of these 

coolers. The problem has been the lack of an adequate understanding 

of the heat transfer of such multi-component mixtures to the walls of 

the heat exchanger, and to a lesser degree an understanding of the 

pressure drop along the exchangers. These factors have limited the 

ability to design more efficient, low cost exchangers needed for 

improved cryocooler performance. Recently we have made progress 

in this area allowing calculation of the heat transfer factors under the 

conditions of use of these exchangers, in reasonable agreement with 

experiment. We describe this work, discuss the potential 

improvements to be expected, and identify remaining issues. 

I am indebted to my colleagues at MMR for comments and 

suggestions. 

C1-Q-03 Micromachined Joule-Thomson coolers 

P.P.P.M. Lerou, H.J.M. ter Brake, H.V. Jansen, J.F. 

Burger, H.J. Holland, H. Rogalla, University of 

Twente. 

A MEMS-based Joule-Thomson cold stage was designed and 

prototypes were realized and tested. The cold stage consists of a stack 

of three glass wafers. In the top wafer, a high-pressure channel is 

etched that ends in a flow restriction with a height of typically 300 

nm. An evaporator volume crosses the center wafer into the bottom 

wafer. This bottom wafer contains the low-pressure channel thus 

forming a counter-flow heat exchanger. A design aiming at a net 

cooling power of 10 mW at 96 K and operating with nitrogen as the 

working fluid was optimized based on the minimization of entropy 

production. The optimum cold finger measures 28 mm x 2.2 mm x 0.8 

mm operating with a nitrogen flow of 1 mg/s at a high pressure of 80 

bar and a low pressure of 6 bar. A batch of 14 prototype coolers was 

made in 8 different designs. Liquid nitrogen is collected in the 

evaporator, and since the low pressure is 6 bar, the temperature should 

be 96 K. However, because of thermal resistance between the bath 

and the thermocouple a temperature was measured of 105 K with a net 

cooling power of 5 mW. In the paper, the design and fabrication of the 

coolers will be discussed along with experimental results. A specific 

issue that will be addressed is the clogging of the restriction due to the 

deposition of ice crystals. 

C1-Q-04 Performance of a MEMS Heat Exchanger for a 

Cryosurgical Probe 

M.J. White, G.F. Nellis, S.A. Klein, Dept. of 

Mechanical Engineering, Univ. of Wisconsin- 

Madison; W. Zhu, Y.B. Gianchandani, Dept. of 

Mechanical Engineering, Univ. of Michigan-Ann 

Arbor; D.W. Hoch, Dept. of Mechanical Engineering, 

Univ. of North Carolina-Chapel Hill. 

This paper presents the experimental results of a 2nd generation 

Micro-Electro-Mechanical Systems (MEMS) heat exchanger that is a 

composite of silicon plates with micromachined flow passages 

interleaved with glass spacers. The MEMS heat exchanger was 

designed for use as the recuperative heat exchanger within the Joule- 

Thomson cycle used to energize a cryosurgical probe. 

The experimental measurements are compared with the numerical 

predictions from a design model and also with experimental results 

obtained from a 1st generation MEMS heat exchanger. The 1st 

generation heat exchanger was unable to withstand the high pressure 

differences (1400 kPa) required by a J-T cryosurgical probe. The 2nd 

generation heat exchanger addresses these design deficiencies and 

exhibits superior thermal performance. Several prototypes of the 2nd 

generation heat exchanger have been manufactured and tested over a 

range of conditions. 

This work was funded by the University of Michigan through a grant 

from the US National Institute of Health, NIH/NINBS R21 EB003349- 

01. 

C1-Q-05 High Frequency Pressure Oscillator for 

Microcryocoolers 

S. Vanapalli, Y. Zhao, R. Sanders, H.J.M. terBrake, 

M.C. Elwenspoek, MESA+ Institute of 

Nanotechnology, University of Twente. 

Regenerative type of microcryocoolers has to operate at higher 

frequencies compared to the typical operating frequency of Stirling or 

Pulse tube coolers owing to higher parasitic losses. Conventional 

linear motors used in pulse tube cryocoolers cannot be scaled down to 

frequencies of about 1 KHz due to increase in various losses. Piezo 

electric motor driven membrane type pressure oscillator provide an 

alternative choice in going to higher frequencies. In this paper we aim 

to present the design and operation of a piezo driven oscillator at 

frequencies of about 1 KHz and a filling pressure of 2.5 MPa. A 

pressure ratio of about 1.1 is achieved. Modelling of the pressure 

oscillator and comparison with experiments will also be presented. 

STW-Dutch Technology Foundation for financial support 



C1-Q-06 Piezo-Hydraulic Actuation for Driving High 

Frequency Miniature Split-Stirling Pulse Tube 

Cryocoolers 

I. Garaway, G. Grossman, Technion - Israel Institute 

of Technology. 

In recent years piezoelectric actuation has been identified as a 

promising means of driving miniature Stirling devices. It supports 

miniaturization, has a high power to volume ratio, can operate at 

almost any frequency, good electrical to mechanical efficiencies, and 

potentially has a very long operating life. The major drawback of 

piezoelectric actuation, however, is the very small displacements that 

this physical phenomenon produces. This study shows that by 

employing valve-less hydraulic amplification, an oscillating pressure 

wave can be created that is sufficiently large to drive a high frequency 

miniature pulse tube cryocooler (as high as 350 Hz in our 

experiments, and perhaps higher). Beyond the direct benefits 

derived from using piezoelectric actuation there are further benefits 

derived from using the piezo-hydraulic arrangement with membranes. 

Due to the incompressibility of the hydraulic fluid the actuator may be 

separated from the main body of the cryocooler by relatively large 

distances with almost no detrimental effects, and the complete lack of 

rubbing parts in the power conversion processes makes this type of 

cryocooler extremely robust. The design and experimental device 

along with some test results will be presented. 

C1-Q-07 Demonstration of a superconducting detector 

cooled by electron-tunneling refrigerators 

J.N. Ullom, J.A. Beall, W.D. Duncan, F. Finkbeiner, 

G.C. Hilton, K.D. Irwin, D.R. Schmidt, L.R. Vale, 

NIST; N.A. Miller, G.C. O`Neil, NIST/University of 

Colorado Boulder; D.J. Benford, J.A. Chervenak, 

S.H. Moseley, R.F. Silverberg, NASA GSFC; T.C. 

Chen, Global Science and Technology. 

We have successfully cooled a Transition-Edge Sensor (TES) using 

thin-film, solid-state refrigerators based on Normal metal/ 

Insulator/Superconductor (NIS) tunnel junctions. The cooling 

mechanism is the preferential tunneling of the highest energy (hottest) 

electrons through the biased NIS junctions. We describe the cooling 

performance, temperature noise, and energy resolution of the NIScooled 

TES. In particular, we show that the NIS refrigerators 

introduce no detectable noise in the TES operation. We also describe 

ongoing efforts to improve the cooling performance of NIS 

refrigerators and the ease with which they can be coupled to usersupplied 

payloads. NIS refrigerators can cool from temperatures near 

0.3 K to below 0.1 K. The calculated power dissipation to cool 1,000 

thin-film sensors is 1-10 microWatts. Combining a pumped He-3 

system with NIS refrigerators provides a compact, lightweight 

alternative to adiabatic demagnetization refrigerators and dilution 

refrigerators. 

Wednesday, 07/18/07 Plenary 

8:00am - 9:00am 

C2-A Wednesday Plenary Session 

Wednesday, 07/18/07 Oral 

9:00am - 10:30am 

C2-B He II Heat Transfer and Fluid 

Mechanics - II 

C2-B-01 An experimental study of He II two-phase flow 

in a long horizontal pipe 

M. Takahashi, T. Kuriyama, T. Yazawa, I. Watanabe, 

K. Nakayama, Toshiba Corp.; Y. Ota, T. Okamura, 

Tokyo Tech. 

Superconductor cavities used in linear collider are cooled below 2K in 

superfluid helium to enhance the generated electric field. In some 

linear collider such as planned in the International Linear Collider 

project (ILC), the cryogenic system will have a considerably long 

horizontal pipe, more than hundred meters, in which two-phase 

superfluid helium flows. One of the key issue for the cryogenic design 

is the gradient of the liquid level in the pipe. It should be designed as 

small as possible to cause the dry-out at somewhere of the pipe. We 

have developed a test apparatus of He II two-phase flow in a long 

pipe. The apparatus is comprised mainly of a He II vessel, a twophase 

flow pipe with 4 m in length and 32 mm in diameter, and some 

cavity vessels. Instead of cavities, electric heaters gave the thermal 

load. The gradient of the liquid level as a function of the load was 

measured by using two level meters. The experimental results were 

compared to numerical results. 

C2-B-02 Experimental facility for comparison of high 

Reynolds number turbulence in both HeI and HeII : first 

results 

B. Rousset, M. Bon Mardion, D. Communal, F. 

Daviaud, P. Diribarne, B. Durbrulle, A. Forgeas, A. 

Girard, P. Roussel, CEA; C. Baudet, Y. Gagne, P; 

Thibault, UJF; B. Castaing, ENS; B. Hebral, P. 

Roche, CNRS. 

Turbulence SuperFluid (TSF) project will use cryogenic liquid helium 

for the fundamental study of turbulent phenomena. For this purpose 

we have carried out an experiment of passive grid turbulence which is 

able to work in HeI as well as in HeII. The flow of liquid helium will 

be generated by a cold Barber and Nichols circulating pump, whereas 

helium flow temperature is kept constant by means of a heat 

exchanger immersed in a saturated bath, which mainly evacuates the 

heat due to friction. 

This experiment will use the CEA Grenoble refrigerator (nominal 

capacity of 400 Watt at 1.8 K) to remove the heat due to pressures 

losses in this high Reynolds number experiment. In order to solve the 

Kolmogorov scale associated with such high flow local 

instrumentation (e.g. sub-micrometer anemometer) was developed. 

Use of this local and fragile instrumentation in a quasi industrial 

environment arises some difficulties we discussed here while the 

solutions adopted are also described. 

Finally, first results obtained both in superfluid and in normal helium 

are presented. For this last case, a permanent mass flow rate of few 

hundreds of g/s was achieved. 

C2-A-01 The COBE Mission: How Cryogenics is 

Revolutionizing Astronomy and Astrophysics 

J. Mather, NASA/Goddard Space Flight Center. 

The development of deep cooling for space science applications has 

enabled an extraordinary series of discoveries in astrophysics, ranging 

from infrared astronomy to X-ray astronomy and tests of general 

relativity to observations of the Big Bang itself. I will describe the 

instrument package and the cooling concepts used on the Cosmic 

Background Explorer satellite, and the scientific results that led to the 

Nobel Prize in Physics for 2006. The James Webb Space Telescope, 

now in preparation for launch in 2013, will use both radiative and 

active cooling to extend the science of the Hubble Space Telescope 

and the Spitzer Space Telescope. I will discuss the cooling concepts 

for these missions and others, and speculate on the future of 

cryogenics in space science. 



C2-B-03 Pressure drop and heat transfer in He II forced 

flow through orifice plates 

H.J. Kim, S.W. Van Sciver, FAMU-FSU College of 

Engineering / National High Magnetic Field 

Laboratory; S. Fuzier, National High Magnetic Field 

Laboratory. 

Forced flow superfluid helium (He II) through orifice plates at the 

high Reynolds number has been experimentally investigated. The 

flow of He II is generated with a bellows pump through a 1 m long, 73 

mm inner diameter tubular channel containing three sizes of orifice 

plates: the ratios of orifice diameter to tube diameter are 10 %, 25 % 

and 50 %. The experimental channel is instrumented with eight 

thermometers, a film heater and two differential pressure transducers. 

Pressure drops in He II for adiabatic forced flow were measured 

across the orifice plates and compared with correlations for classical 

fluids at high Reynolds number. The temperature drops in He II 

forced flow in orifice plates were measured, and found to agree with 

the isenthalpic expansion. The heat generated by a film heater located 

three diameters upstream of the orifice plate generates counterflow in 

the He II resulting in local temperature in the vicinity of the orifice 

plates. These results are compared to predictions based on the two 

fluid model. 

This work is supported by the Department of Energy, Division of High 

Energy Physics. Thanks to Scott Maier for technical assistance. 

C2--B-04 Extraction of micron-sized particles from a He 

II bath 

M. Gnos, S. Fuzier, S.W. Van Sciver, NHMFL, 

Florida State University. 

Our laboratory is developing a new technique to separate micron and 

possibly submicron size particles by size using superfluid helium (He 

II). A heat current in the He II generates normal fluid flow which in 

turn drags particles of different sizes into different sections of an 

experimental channel immersed in a He II bath. In the present paper, 

we describe a technique developed to extract the particles from the 

separation channel while it is immersed in the helium bath. In situ 

extraction allows for a continuous process of separation without 

having to warm up the cryostat and disassemble the channel. A tube is 

inserted from the room temperature environment to the area in the 

channel collecting the particles to be extracted. This tube is closed at 

the bottom by a multibore tube cylinder and is pumped to a lower 

pressure that the helium bath. The pressure gradient through the 

multibore tubes creates a temperature gradient which drives the 

normal component of the He II and the particles into the tube. The 

particles can then be collected and extracted by pulling the tube out of 

the bath. We compare the performance of this device for extraction of 

polymer and hollow glass sphere particles of sizes varying between 

1.7 and 12 micrometers. 

Work supported by Oxford Instruments 

C2-B-05 3-D Numerical Analysis for Heat Transfer from 

a Fat Plate in a Duct with Contractions Filled with 

Pressurized He II 

D. Doi, Y. Shirai, M. Shiotsu, Kyoto University. 

A computer code of three-dimensional heat transfer in superfluid 

helium named SUPER-3D was developed based on the two-fluid 

model. Critical heat fluxes (CHFs) on a flat plate located at one end of 

rectangular ducts having contractions with different rectangular open 

area were calculated by using the SUPER-3D for the liquid 

temperatures from 1.8 K to 2.1 K in pressurized He II. The analyses 

were made for the ducts with one contraction (Case A) and with two 

contractions (Case B). In case A, effects of the open mouth area, 

distance of the contraction from the flat plate and of the open mouth 

figure with the same area were clarified. The solutions of CHF for the 

various open mouth areas agreed well with the experimental data. In 

Case B, the solutions of CHF for the two contractions with the same 

open areas were affected by the combination of open mouth figures. 

It was found from the analysis that several vortices were generated 

around the contractions and played an important role in determining 

the CHF. Three dimensional analyses are necessary to evaluate the 

CHF accurately. 

Wednesday, 07/18/07 Poster 

9:00am - 10:30am 

C2-C Stirling and Pulse Tube Components 

and Modeling (Aerospace) 

C2-C-01 10K EM Pulse Tube Cooler 

C. Jacob, T. Nguyen, R. Colbert, J. Raab, Northrop 

Grumman Space Technology. 

A 3 stage Engineering Model pulse tube cooler was built and tested 

for low temperature operations. The staged cooler uses the same 

compressor and parallel staging configuration for the 1st and 2nd 

stages previously employed in the Flight Qualified High Capacity 

Cryocooler (HCC Qual). Addition of the third stage extends the 

performance of this cooler to operating temperatures below 10K. 

The cooler performance at 10K has been characterized and test data 

will be presented. 

C2-C-02 Numerical Study of Thermoacoustically-driven 

Pulse Tube Cooler 

With Spring-Mass Resonators 

W. Dai, Z. Wu, S. Zhu, E. Luo, Technical Institute of 

Physics and Chemistry. 

Thermoacoustically-driven pulse tube cooler could be heat-driven and 

offer the advantages of being simple and highly reliable. Normal 

thermoacoustic engines with a long resonance tube to control the 

frequency face the problems of large thermoviscous dissipation, 

oversize and structural vibrations, etc, which is not good for practical 

small-scale applications. One solution is to use dual-opposed springmass 

resonator to replace the resonance tube, which could ensure the 

compact size, low vibration and remains to be simple on structure. 

This article uses the linear thermoacoustic theory to simulate such a 

configuration working at frequencies between 100~500Hz, which 

aims at small-scale cryogenic applications. The influence of springmass 

resonator parameters, operating conditions, coupling positions 

and other factors are studied. 

This work is financially supported by National Natural Science 

Foundation with project number 50506031. 

C2-C-03 Linear resonant moving magnet type motor for 

miniature pulse tube cryocooler 

B.T Kuzhiveli, National Institute of Technology 

Calicut. 

More than past two decades, voice coil type moving coil linear motors 

have been in wide use for the 

construction of various miniature cryocoolers. However they are 

haunted by its inherent life limiting problems such as rupture of lead 

wires, out gassing by the coil lamination etc. A recent tendency is to 

replace the moving coil type motor with moving magnet type motor 

for the compressor. Recent advances in miniature pulse tube 

cryocooler technology have made them surpass most of the miniature 

cryocoolers operating on other cooling cycles. The reasons attributed 

for this change are due to the advantages such as improved overall 

efficiencies, reduced number of moving parts, no vibration in cold 

head and suitability to use with moving magnet type motor etc. In 

this context splendid of scope exists for understanding new trade offs 

in technology of moving magnet type motor, design and evaluation of 

performance parameters and its comparison with moving coil type 

motor. A design methodology has been developed for the 

development of moving magnet and moving coil type linear motors. 

Computer code has been written down for motor optimisation and has 

been used for the design of motors. 



C2-C-04 An aerospace miniature pulse tube cryocooler at 

80K 

H.L. Chen, L.W. Yang, J.H. Cai, J.T. Liang, Y. Zhou, 

Technical Institute of Physics and Chemistry, CAS. 

An engineering model of a miniature pulse tube cryocooler is 

designed for space application. Coaxial configuration of the cold 

finger is convenient to connect with the aim element and improves 

integration. A series of jointing cooler products are manufactured and 

tested. The overall mass of the whole cooler system is around 3.5kg. 

The product coolers can provide 0.7W cooling capacity at 80K within 

40W input electric power, while the experimental ones can proveide 

more than 0.8W cooling capacity. To make a product for space 

application, intense structure, light weight and small size are needed, 

so different materials and structures et al. decrease the cooling 

performance more or less. Reliability of the cooler working 

continously is tested. Also, the magnetic field of the compressor and 

anti-shake ability of the system has been examined. 

C2-C-05 Investigation of a 500Hz heat-driven pulse tube 

cooler by using etched foil regenerator 

S.L. Zhu, Graduate University of Chinese Academy of 

Sciences; E.C. Luo, Technical Institute of Physics and 

Chemistry, CAS; W. Dai, Technical Institute of 


A thermoacoustically-driven high frequency pulse tube cooler has the 

advantage of being compact, which has good potential of using for 

aerospace cooling. This article presents a pulse tube cooler driven by a 

traveling-wave thermoacoustic engine with a working frequency 

around 500 Hz. As operating frequency increases, a traditional screenpacked 

regenerator is limited by the requirement of smaller wire 

diameter and higher mesh number of the screens. In this pulse tube 

cooler, however, we have used the etched foil regenerator instead of 

the screen-packed regenerator to decrease flowing loss, which shows 

more important impact on the global performance of the whole system 

when the operating frequency goes up to 500Hz. Experiments has 

been conducted to investigate the characteristics of the pulse tube, 

which includes the structure parameters of the novel regenerator and 

the operating parameters including mean pressure, inlet pressure ratio, 

inertance tube phase shifter. Numerical simulation results are also 

made and compared with the experiment results in the same condition. 



C2-C-06 Performance of a two stage Stirling cryocooler 

for space applications 

V.K. Bhojwani, M.D. Atrey, S.L. Bapat, Indian 

Institute of Technology Bombay, Mumbai, India; K.G. 

Narayankhedkar, Veermata Jijabai Technological 

Institute, Mumbai, India. 

A two-stage, split type Stirling cryocooler with capacity of 2 W at 100 

K and 0.5 W at 50 K is designed. Second order cyclic analysis is used 

to decide the final geometry of the unit. The compressor with opposed 

pistons configuration is developed. Flexure stacks suspended piston 

and displacer are used. Moving coil linear motor is developed. 

Sensors are installed for measuring strokes of pistons and displacer; 

and pressure at the outlet of the compressor. 10 channel oscilloscope 

provides the variations of parameters. The load tests indicated that the 

cooling capacities are close to the design values. The power input for 

the compressor is 110 W as against 69 W predicted by the analysis. 

The experimental no load temperature for the stage I is observed to be 

close to the predicted temperature. Two identical expanders are 

developed to check the repeatability. For expander I, the temperatures 

attained for a load of 2 W on stage I and 0.5 W on stage II are 106 K 

and 74 K respectively with a power input of around 110 W. The 

corresponding values for expander II are 128 K, 66.7 K with a power 

input of 105.6 W. 

The authors thank Indian Space Research Organisation for financial 

support. 

C2-C-07 A model for the parametric analysis and 

optimization of inertance tube pulse tube refrigerators 

C Dodson, A Razani, AFRL/VSSS-UNM; A Lopez, 

UNM/Sandia National labs; T Roberts, AFRL/VSSS. 

A first order model developed for the design analysis and optimization 

of Inertance Tube Pulse Tube Refrigerators (ITPTRs) is integrated 

with the code NIST REGEN 3.2 capable of modeling the regenerative 

heat exchangers used in ITPTRs. The model is based on the solution 

of simultaneous non-linear differential equations representing the 

inertance tube, an irreversibility parameter model for the pulse tube, 

and REGEN 3.2 to simulate the regenerator. The integration of 

REGEN 3.2 is accomplished by assuming a sinusoidal pressure wave 

at the cold side of regenerator. In this manner the computational 

power of REGEN 3.2 is conveniently used to reduce computational 

time required for parametric analysis and optimization of ITPTRs. 

The exergy flow and exergy destruction (irreversibility) of each 

component of ITPTRs is calculated and the effect of important system 

parameters on the second law efficiency of the refrigerators is 

presented. 

C2-C-08 Reliability Growth of Stirling-Cycle Coolers at 

L-3 CE 

D.T. Kuo, A.S. Loc, Q.K. Phan, L-3 Communications - 

Cincinnati Electronics. 

L-3 Communication is conducting a reliability growth program to 

extend the life of tactical Stirling-cycle cryocoolers. The continuous 

product improvement processes consist of testing production coolers 

to failure, determining the root cause, incorporating improvements 

and verification. The most recent life test data for the 0.6-Watt Cooler 

(Model B600C), The 1.5-Watt Cooler (Model B1500E), and the Gas 

Bearing 1.0-Watt Cooler (Model GB1000E) are presented. From the 

life test data, sets of empirical constants are derived for life prediction, 

for any operating condition using the Watt-Hour approach. The data 

presented here extends the boundary of life data in previous papers 

from the authors. 

C2-C-09 Performance Optimization of L-3 CE 0.6-Watt 

Linear Cooler 

D.T. Kuo, A.S. Loc, L-3 Communication - Cincinnati 

Electronics. 

Tactical FLIR are placing increasing demand for cryocoolers to 

deliver more performance without commensurate size and weight 

allowances. L-3 CE has re-optimized the design of its 0.6-Watt cooler 

to provide twice the refrigeration lift without significant changes to 

weight and size. This paper presents the performance characteristics 

of the re-optimized cooler model B610. 

C2-D Large Scale Aerospace Test Facilities 

C2-D-01 Large-Scale Test Facility for Advanced 

Cryogenic and Energy Technology Development 

W.H. Hatfield, Sierra Lobo, Inc.; D.E. Taylor, J.P. 

Sass, NASA KSC. 

NASA has completed initial construction and verification testing of 

the Integrated Systems Test Facility (ISTF) Cryogenic Testbed. The 

ISTF is located at Complex 20 at Cape Canaveral Air Force Station, 

Florida. The remote and secure location is ideally suited for the 

following functions: (1) development testing of advanced cryogenic 

component technologies, (2) development testing of concepts and 

processes for entire ground support systems designed for servicing 

large launch vehicles, and (3) commercial-sector testing of cryogenicand 

energy-related products and systems. The Cryogenic Testbed 

consists of modular fluid distribution piping and storage tanks for 

liquid oxygen/nitrogen (56,000 gal) and liquid hydrogen (66,000 gal). 

Storage tanks for liquid methane (41,000 gal) and Rocket Propellant 1 

(37,000 gal) are also specified for the facility. A state-of-the-art 

blastproof test command and control center provides capability for 

remote operation, video surveillance, and data recording for all test 

areas. 



C2-D-02 Cryogenic Propellant Tank Facility (K-SITE) at 

NASA`s Plum Brook Station 

J.A. Chambers, D.E. Taylor, J.M. Woytach, NASA 

GRC. 

The Cryogenic Propellant Tank Facility is multipurpose cryogenic and 

space simulation test facility. The 25 foot diameter test chamber has a 

20 foot diameter door, removable LH2/LN2 cryogenic cold wall 

capable of simulating deep space temperatures down to 37deg R (- 

423deg F) and a unique hydraulic shaker system. The facility can 

provide vacuum to 10-6 torr without the cold wall and 10-8 torr with 

the cold wall in operation. An 800-gallon slush hydrogen batch 

production plant is also available. The facility’s design and 

construction provides a safe environment for testing with high energy 

fluids. K-Site is ideally suited for performing a broad range of 

cryogenic experiments including performance testing of sensors and 

insulation systems, cryogenic storage tank boil-off and slosh tests, 

turbopump chill-down and start-up tests, Lunar surface simulation, 

and fuel cell development tests. The versatility of K-Site makes the 

possibilities almost endless. Build-up is supported by an on-site 

machine shop, rough build area and 40-foot high-bay immediately 

adjacent to the test chamber. A highly trained and competent 

technical staff is on-site to provide design, fabrication, installation and 

operations support. A large exclusion zone surrounding K-Site makes 

it ideal for high-risk propellant related programs. 

C2-D-03 The Cryogenic Components Laboratory (CCL) 

at NASA`s Plum Brook Station 

J.A. Chambers, D.E. Taylor, J.M. Woytach, NASA 

GRC. 

The Cryogenic Components Laboratory is a new, state-of-the-art 

facility for research, development and qualification of cryogenic 

materials, components and systems. This facility provides systems 

and capabilities for cryogenic testing with liquid hydrogen, oxygen 

and nitrogen. These systems are highly re-configurable to meet a 

broad range of test requirements and parameters. A highly trained and 

competent technical staff is on-site to provide design, fabrication, 

installation and operations support. Run tank capacities and high 

gaseous nitrogen flow rates make the facilities well suited for 

cryogenic high-speed turbomachinery, bearing and seal testing. Large 

on-site storage capacities provide capability for extended run times. 

The facility’s electrical design classification provides a safe 

environment for testing with high energy fluids. Liquid hydrogen and 

liquid oxygen densification skids capable of densifying propellants at 

rates up to 8 pounds-per-second are available. The state-of-the-art 

control room provides remote data acquisition and programmable 

logic control (PLC) for personnel and systems safety. The dual 

configuration design of the facility allows for build-up and operation 

of multiple simultaneous users. A large exclusion zone surrounding 

the CCL makes it ideal for high-risk propellant related programs. 

C2-D-05 Large Cryogenic System for Space Environment 

Simulation 

H. Cho, G.-W. Moon, H.-J. Seo, S.-H. Lee, S.-W. 

Choi, Korea Aerospace Research Institute. 

KARI (Korea Aerospace Research Institute)’s thermal vacuum 

chamber with 9 meters diameter and 10 meters depth was completed 

at the end of November 2006 being equipped with large cryogenic 

system for space environment. Cryogenic system enables a thermal 

shroud inside the vacuum chamber to be cooled down to 77 K with 

liquid nitrogen, which provides surrounding deep space environment 

for a satellite. This cryogenic system basically utilizing gravitational 

potential energy of stored liquid nitrogen in 10 meters height, is 

composed of phase separator, liquid nitrogen pump, cryogenic valve, 

vacuum jacketed pipes, liquid nitrogen exhaust system, and heated 

gaseous nitrogen purge system. Through several acceptance tests for 

the cryogenic system, it was verified that thermal shroud can be 

cooled from 295 K to 77 K within 30 minutes, temperature drift when 

the shroud is in steady condition is less than 2 K. Liquid nitrogen 

exhaust system and heated gaseous nitrogen purge system made an 

improvement for reducing of the time to increase the chilled shroud 

temperature up to ambient temperature, which could shorten the total 

satellite test duration. Test results and detail specifications of the 

cryogenic system including liquid nitrogen boil-off and consumption 

were described. 

C2-D-06 The Development of the Cooling and Heating 

Device in the Test Facility for Space Tribological 

Simulation Experiment 

L.H. Gong, X.D. Xu, R.J. Huang, L.F. Li, Technical 

Institute of Physics and Chemistry, Chinese Academy 

of Sciences; X.J. Sun, W.M. Liu, Space Tribology 

Center, Lanzhou Institute of Chemical 

Physics,Chinese Academy of Sciences. 

The cooling and heating device in the test facility for space 

tribological experiment has been developed and tested. The device 

consists of a sample holder, a heater and an annular liquid nitrogen 

heat sink. The sample holder surrounded by a heater is located in the 

core of the heat sink. The holder, heater and heat sink, which almost 

have no any heat conduction among them, are closed in the high 

vacuum vessel (10E-7Pa). Therefor, the principle of the radiation heat 

transfer has been adopted for cooling and heating of the tribological 

sample because of the rotation of the sample holder which is 

connected to a long axes driven by the magnetic force. Some 

techniques have been introduced into the design in order to speed up 

the cool down rate of the sample, such as, the surface of the heater and 

the inside surface of the annular heat sink have been blacked and the 

special material and unique structure have been used for the axes of 

the sample holder. 

Test results show that the highest heating temperature can be about 

600K, and the lowest cooling temperature can reach around 130K. 

The cooling time is roughly two days. The sample temperature can be 

stabilized at any point with accuracy of 0.2K in the range of 

130~600K. The heat transfer analysis, temperature control & display 

and test results of the cooling and heating device have been presented. 

And some considerations have been discussed to improve the slow 

cool down rate in the future. 

C2-E Regenerators 

C2-E-01 A Low-Temperature Regenerator Test Facility 

A. Kashani, B.P.M. Helvensteijn, Atlas Scientific; J.R. 

Feller, L.J. Salerno, NASA-Ames Research Center; P. 

Kittel, Consultant. 

Testing regenerators presents an interesting challenge. When 

incorporated into a cryocooler, a regenerator is intimately coupled to 

the other components. It is difficult to isolate the performance of any 

single component. We have developed a low temperature test facility 

that separates the performance of the regenerator from the rest of the 

cryocooler. The purpose of the facility is the characterization of test 

regenerators using novel materials and/or geometries in temperature 

ranges down to 15 K. The test column consists of two regenerators 

stacked in series. The coldest stage regenerator is the device under 

test. The warmer stage regenerator consists of a stack of wellcharacterized 

material such as stainless-steel screen. A commercial 

cryocooler is used to cool the heat exchangers in the regenerator stack. 

The cryocooler is used to fix the temperatures at both ends of the test 

regenerator. Heaters on each cryocooler stage add the capability to 

vary the temperatures and allow measurement of the remaining 

cooling power, and thus, regenerator effectiveness. A linear 

compressor delivers an oscillating pressure to the the regenerator 

assembly. An inertance tube and reservoir provide the proper phase 

difference between mass flow and pressure. This phase shift, along 

with the imposed temperature differential, simulates the conditions the 

test regenerator might see when used in an actual cryocooler. This 

paper presents development details of the regenerator test facility. 



C2-E-02 Hybrid Regenerator for Compact Stirling 

Cryocooler Design aspectes of a compact hybrid 

regenerator for pulse tube cryocooler application 

B.T. Kuzhiveli, National Inst. of Technology Calicut. 

A study has been conducted to find out the optimum configuration of 

regenerators to be used for miniature cryocoolers. Mesh sizes starting 

with 200 up to 400 with an interval of 50 have been sampled and 

performance estimation has been made. The study has been extended 

to determine the performance of a hybrid regenerator and its 

suitability to use in a cryocooler which can produce 5W at 80 K. A 

methodology has been developed to arrive at the appropriate mesh 

size and number of mesh to be used in the hybrid regenerator to go 

hand in hand with the available mass. Results are presented in the 

form of design charts for quick reference which could be helpful in 

the design of miniature regenerators. 

C2-E-03 Dynamic characteristics of oscillating flow 

regenerators 

H.L. Chen, L.W. Yang, J.H. Cai, J.T. Liang, Y. Zhou, 

Technical Institute of Physics and Chemistry, CAS. 

Regenerator is the most important component in a pulse-tube 

cryocooler. Because of oscillating flow, heat transfer and flow 

resistance in the regenerator are complex, and phase shifts between 

parameters affect the cooling performance evidently. Regenerator 

research is a fundamental work for cryocoolers. Experiments are 

performed to test regenerators of different size filled with different 

mesh number screens. Two fine hot-wire anemometers are used to 

measure the instantaneous velocities at the inlet and outlet of the 

regenerators, and the pressure waves are measured by piezoelectric 

pressure transducers at the same positions. The responding frequency 

of the measuring system is high enough. 

In the past, we have performed experiments to study the oscillating 

flow at around 50Hz.In this paper, the system is driven by a 

thermoacoustic engine which generates a pressure wave at 300Hz. 

The two kinds of results are compared and analyzed. 

C2-E-04 Analysis of Cryogenic Regenerator for Magnetic 

Refrigerator Applications 


Calicut; R. Chahine, T.K Bose, Institut de recherche 

sur l’hydrogène, Université du Québec; C.B. Zimm, 

Astronautics Corporation of America. 

Magnetic refrigeration uses the temperature and field dependence of 

the entropy of specific magnetic materials to accomplish cooling. 

Because of the high efficiency of the magnetization and 

demagnetization processes and also because of the potential for 

excellent heat transfer between solid magnetic material and fluids, 

magnetic refrigerators may promise to have higher efficiency than 

existing gas cycle refrigerators. Many ground based and space borne 

applications could benefit significantly from the cost savings implied 

by efficiency. This paper deals with a basic computational model 

which could predict the temperature drop caused by the regenerator 

effect. It solves partial differential equations that describe fluid flow 

combined with heat transfer between fluid and solid regenerator 

particles. Temperature changes are calculated for discrete material 

segments at a number of time intervals over a complete operation 

cycle. A numerical step-by-step procedure to solve the differential 

equations describing the regenerative heat exchanger is set out and a 

computer program has been made to predict performance of the 

regenerator. 

C2-E-05 Second-Law Analysis and Optimization of 

Regenerators Using REGEN 3.2 

A.J. Lopez, The Univ. of Nex Mexcio; Sandia Nat`l 

Laboratories; C. Dodson, A. Razani, The Univ. of New 

Mexico; Air Force Research Lab.. 

In most Stirling and pulse tube refrigerators the regenerative heat 

exchanger is the major contributor to the irreversibility of the 

refrigerators. Exergy analysis is a convenient method to quantify the 

losses in regenerators. NIST Code REGEN 3.2 provides a powerful 

tool to quantify exergy flow in the regenerators to evaluate the exergy 

destruction (irreversibility) due to heat transfer and fluid friction. The 

effect of important parameters, with emphasis on the phase shift 

between the pressure and the mass flow rate at the cold side of 

regenerator, on the exergetic efficiency and the important components 

of exergy destruction in the regenerator is presented. The efficiency 

of the regenerator based on exergy analysis is compared to other 

methods of evaluating regenerator performance. The ability of the 

code to quantify the exergy flow and destruction at low temperatures 

where the ideal gas assumption is not applicable is discussed. 

C2-E-06 Longitudinal Hydraulic Resistance Parameters 

of Cryocooler and Stirling Regenerators in Steady Flow 

W.M. Clearman, S.M. Ghiaasiaan, P.V. Desai, G.W. 

Woodruff School of Mechanical Engineering Georgia 

Institute of Technology. 

The results of an ongoing research program aimed at the measurement 

and correlation of anisotropic hydrodynamic parameters of widelyused 

cryocooler regenerator fillers are presented. The hydrodynamic 

parameters associated with steady, longitudinal flow are addressed in 

this paper. An experimental apparatus consisting of a cylindrical test 

section packed with regenerator fillers is used for the measurement of 

axial permeability and Forchheimer coefficients, with pure helium as 

the working fluid. The regenerator fillers that are tested include 

stainless steel 400-mesh screens with 69.2% and 62% porosity, 

stainless steel 325-mesh screens with 69.2% and 62% porosity, 

stainless steel 400-mesh sintered filler with 62% porosity, and 

stainless steel sintered foam metal with 56% porosity. The test section 

is subjected to a steady flow of helium at one end, and is open to the 

atmosphere at the other end. The instrumentation includes pressure 

transducers and a high-precision flow meter. For each filler material, 

time histories of local pressures at inlet to the regenerator are 

measured under steady flow conditions over a wide range of flow 

rates. A CFD assisted methodology is then used for the analysis and 

interpretation of the measured data. The permeability and 

Forchheimer parameter values obtained in this way are then correlated 

in terms of the relevant dimensionless parameters. 




10:30am - 11:45am 

C2-G Low Temperature Superconducting 

Magnet Systems III 

C2-G-01 ATLAS Superconducting Magnet System Status 

of Completion 

H.H.J. Ten Kate, CERN. 

The superconducting magnet system of the ATLAS Detector at CERN 

comprises a Barrel Toroid, two End-Cap Toroids and a Central 

Solenoid and it provides the magnetic field for the muon- and inner 

detectors, respectively. The huge Barrel Toroid with outer dimensions 

of 25m length and 20m diameter is built up from 8 identical racetrack 

coils, each of them already unique in size. The coils are wound with 

an aluminium stabilised NbTi conductor and operate at 20.5kA at 

3.9T peak magnetic field in the windings. The coils, in total 370 tons 

of cold mass, are conduction cooled at 4.8K by circulating forced flow 

helium in cooling tubes attached to the cold mass. The two End Cap 

Toroids are smaller sized, still 11m in diameter and 5m in height, 

essentially made with the same superconductor and operates also at 

20.5kA. The Central Solenoid has dimensions of 2.4m diameter and 

5.7m length. The stored energy of the magnet system is 1.5GJ at 

nominal current. After the successful on-surface acceptance tests, the 

8 coils of the Barrel Toroid and the Solenoid were installed in the 

ATLAS cavern 100m underground. The magnets were successfully 

charged to full field in autumn 2006. The two End Cap Toroids were 

completed in spring 2007 and are taken into operation as well thereby 

completing this very challenging magnet system. The status of project 

in its nearly completed state as well as the first experience with testing 

and operation of the system in the underground cavern is reported. 

This research is financed by the funding agencies and laboratories 

working together in the ATLAS Collaboration. 

C2-G-02 Series-Produced Helium II Cryostats for the 

LHC Magnets: Technical Choices, Industrialization, 

Costs 

A. Poncet, V. Parma, CERN AT-MCS. 

Assembled in 8 continuous segments of approximately 2.7 kms length 

each, the He II cryostats for the 1232 cryodipoles and 474 Short 

Straight Sections (SSS housing the quadrupoles) must fulfill tight 

technical requirements .They have been produced by industry in large 

series according to cost-effective industrial production methods to 

keep expenditure within the financial constraints of the project, and 

assembled under contract at CERN. 

The specific technical requirements of the generic systems of the 

cryostat (vacuum, cryogenic, electrical distribution, magnet 

alignment) are briefly recalled, as well as the basic design choices 

leading to the definition of their components (vacuum vessels, thermal 

shielding, supporting systems, interconnection elements). Early in the 

design process emphasis was placed on the feasibility of 

manufacturing techniques adequate for large series production of 

components, optimal tooling for time-effective assembly methods, 

and reliable quality assurance systems. 

An analytical review of the costs of the cryostats from component 

procurement to final assembly and tests is presented and compared 

with initial estimates, together with an appraisal of the results and 

lessons learned. 

C2-G-04 Design, production and first commissioning 

results of the electrical feedboxes for the LHC 

A. Perin, A. Ballarino, V. Benda, A. Bouillot, S. 

Claudet, R. Folch, M. Genet, S. Koczorowski, L. 

Metral, J. Miles, L. Serio, Ph. Trilhe, R. van 

Weelderen, CERN; K. Polkovnikov, V. Zhabitskiy, 

IHEP, Russia. 

A total of 44 CERN-designed cryogenic electrical feedboxes are 

needed to power the LHC superconducting magnets. The feedboxes 

include more than 1000 superconducting circuits fed by hightemperature 

superconductor and conventional current leads with 

currents ranging from 120 A to 13 000 A. In addition to supplying the 

electrical current to the magnet circuits, they also ensure specific 

mechanical and cryogenic functions for the LHC. The paper focuses 

on the main design aspects and related production operations, and 

gives an overview of specific technologies employed. Results of the 

commissioning of the feedboxes in the first LHC sectors are 

presented. 

C2-G-05 Quench Performance of Nb3Sn cos-theta coils 

made of 108/127 RRP Strands* 

R. Bossert, G. Ambrosio, N. Andreev, E. Barzi, R. 

Carcagno, V.S. Kashikhin, V.V. Kashikhin, M. Lamm, 

F. Nobrega, I. Novitski, Yu. Pischalnikov, M. 

Tartaglia, D. Turrioni, R. Yamada, A.V. Zlobin, 

Fermilab. 

Fermilab is developing a new generation of high field accelerator 

magnets based on Nb3Sn shell-type coils and the wind-and-react 

technology. The high performance Nb3Sn strand produced by Oxford 

Superconducting Technology (OST) using the Restack Rod Process 

(RRP) is considered at present time as a baseline conductor for the 

model magnet R&D program. To improve the strand stability in the 

current and field range expected in magnet models, the number of 

sub-elements in the strand was increased by a factor of two (from 54 

to 108), which resulted in a smaller effective filament size. The 

performance of the 1.0 mm strands of this design was extensively 

studied using virgin and deformed strand samples. Rutherford-type 

cables made of this strand were also tested using a superconducting 

transformer and small racetrack coils. Based on the positive results of 

strand and cable tests, two shell-type dipole coils were fabricated and 

tested using a magnetic mirror configuration. This paper describes the 

parameters of the 108/127 RRP strand and cables, and reports the 

results of strand, cable and coil testing. 

*This work was supported by the U.S. Department of Energy 

C2-H Heat Transfer - I 

C2-H-02 Thermal conductivity of subcooled liquid 

hydrogen 

T.M.F Charignon, D. Celik, NHMFL-Cryolab; A. 

Hemmati, S.W. Van Sciver, NHMFL-Cryolab . 

Here we present thermal conductivity measurements of subcooled 

equilibrium liquid hydrogen in the temperature range from 15 to 23 K 

and under pressures up to 1 MPa. The measurements have been done 

in a horizontal, guarded, flat-plates calorimeter. One dimensional heat 

transfer between the hot and the cold plates of the calorimeter is 

achieved by surrounding the calorimeter plates with two thermal 

guards. Capacitance measured between the calorimeter plates gives a 

precise and accurate gap value for the test cell. A two-stage Gifford- 

McMahon cryocooler provides the cooling power to the calorimeter. 

The absolute temperatures are monitored using platinum resistance 

thermometers calibrated against the saturated vapor-pressure line of 

equilibrium hydrogen. Results reported in this paper are compared to 

data published earlier. The density dependence of thermal 

conductivity is expected to be especially useful for subcooled 

hydrogen transport properties. 

This research has been supported by NASA through the Research 

Initiative for Florida Universities under the grant NAG3-2751. We 

acknowledge technical support from Scott Maier. 



C2-H-03 Viscous Energy Dissipation in Frozen Cryogens 

S.J. Meitner, J.M. Pfotenhauer, M.R. Andraschko, 

University of Wisconsin-Madison. 

ITER is an international research and development project with the 

goal of demonstrating the feasibility of fusion power. The fuel for the 

ITER plasma is injected in the form of frozen deuterium pellets; the 

current injector design includes a batch extruder, cooled by liquid 

helium. A more advanced fuel system will produce deuterium pellets 

continuously using a twin-screw extruder, cooled by a cryocooler. 

One of the critical design parameters for the advanced system is the 

friction associated with the shearing planes of the frozen deuterium in 

the extruder; the friction determines the required screw torque as well 

as the cryocooler heat load. 

An experiment has been designed to measure the energy dissipation 

associated with shearing frozen deuterium. Deuterium gas is cooled 

to its freezing point in the gap between a stationary outer cylinder and 

a rotating inner cylinder. The dissipation is measured mechanically 

and through calorimetric means. The experiment has also been used 

to measure dissipation in other cryogens (e.g., hydrogen and nitrogen) 

as a function of rotational velocity and temperature. This paper 

describes the design and construction of the experiment and presents 

measurements over a range of cryogens and test conditions. 

This work is supported by the U.S. Department of Energy. 

C2-H-04 Study on thermal diffusion in artificial air near 

the critical point 

A Nakano, T Maeda, AIST. 

AIR is absolutely essential for our everyday life and also very 

important in the field of industry. The major part of it is composed of 

nitrogen and oxygen. We investigated the soret effect in artificial air, 

which was nitrogen-oxygen binary mixture with the composition of 

0.791 mole fraction of nitrogen and 0.209 mole fraction of oxygen 

near the critical point. In the case of the artificial air, the Max.- 

Condentherm (MC) temperature and the MC pressure are 131.532 K 

and 3.65187 MPa, respectively. The critical temperature and the 

critical pressure are slightly lower than the MC temperature and the 

MC pressure. We carried out the experiments by using a single stage 

two-chamber cell, which was divided by a porous diaphragm. We 

made a temperature difference between the two chambers. After an 

experiment had run for sufficient time to reach steady state, the 

concentration of oxygen in each chamber was measured by using a 

gas chromatograph. From the experiments, we observed that the 

thermal diffusion factor showed a strong drop near the critical point. 

The thermal diffusion ratio indicated negative and behaved as 3He- 

4He mixture. There has been no report that the thermal diffusion ratio 

of the nitrogen-oxygen system behaves just like the mixture of such 

substances. We discuss the thermal diffusion in the nitrogen-oxygen 

binary mixture near the critical point. 

C2-H-05 Thermal Conductivity of Powder Insulations 

Below 80 K 

M.N. Barrios, Y.S. Choi, S.W. Van Sciver, National 

High Magnetic Field Laboratory. 

The thermal conductivity of powder insulating materials was 

measured at average temperatures ranging from 30 K to 80 K. The 

measuring device consists of two closed, concentric cylinders which 

are suspended inside of a cryostat. The insulation being tested is filled 

into the annular space between the cylinders. A single stage Gifford- 

McMahon cryocooler is thermally anchored to the outer cylinder and 

used to cool the apparatus to a desired temperature range. A heater 

mounted on the inner cylinder generates uniform heat flux through the 

insulating material between the two cylinders. Fourier’s law of heat 

conduction is used to relate the temperature difference between the 

two cylinders and heating power to a bulk effective thermal 

conductivity of the powder insulation. Data is collected for aerogel 

beads and glass bubbles at temperatures between 30 K and 80 K. 

Using the measured thermal conductivity, we obtain the temperature 

distribution in the powder insulation by solving the one-dimensional 

heat diffusion equation. 

This research is supported by NASA-Kennedy Space Center under 

contract NAS1003006. 

C2-H-06 Thermal Conductivity as a Function of 

Contact Pressure, Temperature, and Interface Material 

B.C. Jackson Sr., Everson Tesla Inc.. 

The purpose of this study is to determine the thermal conductivity 

between two copper surfaces as a function of contact pressure and 

interface material at a range of cryogenic temperatures between 4K 

and 100K. The study differs from previous work in that it utilizes 

extended contact pressures and temperatures. This study is needed to 

enable researchers and members of industry to reach improved levels 

of joint performance required for the operation of novel and existing 

devices including superconducting magnet cryostats. The test 

apparatus utilizes a 2-Stage 4.2K GM cryocooler system in 

conjunction with load adjusting devices to accurately adjust the 

contact force between the cryocooler stages and the interface plates. 

Various types of material will be used between the two contact 

surfaces to make up for surface imperfections including Apezion-N 

grease and indium foil. A series of tests will be conducted at specified 

values of contact force and interface material type. Heat applied to the 

interface is continuously varied and the temperature measured. A 

family of curves will be constructed in order to determine the thermal 

conductivity as a function of contact pressure, temperature and 

interface material. The beneficial result of this study will be the 

economical construction of high performance low temperature 

interfaces. 

David M. Rakos Co-Author 

C2-I Aerospace Mission Cooling Systems 

C2-I-01 The NICMOS Cooling System – 5 Years of 

Successful On-Orbit Operation 

F.X. Dolan, M.V. Zagarola, Creare Inc.; W.L. Swift, 

Consultant. 

The NICMOS Cooling System consists of a closed loop turbo- 

Brayton cryocooler coupled with a cryogenic circulator that provides 

refrigeration to the Near InfraRed Camera and Multi Object 

Spectrometer (NICMOS) on the Hubble Space Telescope (HST). The 

cryocooler rejects heat to space through a capillary pumped loop 

connected to radiators mounted on the side of the telescope. The 

system was deployed and integrated with NICMOS by astronauts 

during STS – 109 (Space Shuttle Columbia) in April 2002. It has 

operated continuously without performance degradation since that 

time, maintaining NICMOS detectors at a constant temperature of 77 

K. Miniature, high-speed turbomachines are used in the cryocooler 

and the circulator loop to provide vibration-free, long-life operation. 

A small centrifugal compressor and miniature turboalternator are key 

elements of the closed loop cryocooler. A miniature cryogenic 

centrifugal circulator in a separate pressurized neon loop transports 

heat from the NICMOS instrument to the cryocooler interface heat 

exchanger. This paper describes the development of the system, 

including key operational features, ground and orbital tests prior to its 

on-orbit integration with NICMOS, and operational results during its 

five-year operational history on orbit. 

C2-I-02 The first European turbo-Brayton cooler inorbit: 

experience gained after one year in flight and 

future applications for space 

P. Crespi, J. Guichard, Air Liquide; M.N. de Parolis, 

ESA; J. Chegancas, Astrium. 

In the frame of a contract granted by the European Space Agency and 

ASTRIUM, AIR LIQUIDE has developed the first European turbo- 

Brayton cooler for a space application. This cooler was successfully 

powered on in the International Space Station in July 2006 and has 

been running since then. This paper presents the design of the cooler 

and recalls the main milestones of the development/qualification 

process. The experience gained on the behaviour of the cooler during 

this one year of operation is presented. We also discuss the possibility 

to extend the on-orbit lifetime of the cooler from two years up to 

seven years. Finally, a survey of potential applications of turbo- 

Brayton coolers for space are presented, ranging from zero boil-off 

systems for future launchers to In-Situ Resource Utilization (ISRU) 

systems and focal plane unit cooling for astronomical satellites. 



C2-I-03 Planck Passive Cooler Design, Test and 

Performance 

E. Gavila, J.B. Riti, D. Valentini, Alcatel Alenia 

Space; C. Damasio, ESA. 

Planck Spacecraft, as part of the 4th cornerstone Herschel Planck ESA 

mission, is dedicated to the Cosmic Microwave Background mapping. 

Planck and Herschel satellites will be launched early 2008 on a single 

ARIANEV launcher and inserted into the Lagrange2 point of the 

Earth-Sun system. One of the main features of Planck lies in its 

cryogenic chain, made of a 60K passive cooler, a 20K H2 sorption 

cooler, a Joule Thomson 4K He4 cooler and finally a 0.1K He3He4 

dilution cooler. Thermal aspects, and in particular those related to the 

Passive Cooler, drive in a large part the S/C architecture as well as its 

verification approach. The Passive Cooler is given contradictory tasks 

to cool large Telescope items and to locally heat sink active Coolers at 

60K. The architecture achieving thermal requirements is a black 

painted open honeycomb surface insulated from the warm spacecraft 

by a set of angled shields opened to cold space. Detailed modelling 

was needed to support conception phase and to predict flight and test 

thermal behaviours. Mathematical model had furthermore to be 

populated by material properties data over the 300K-50K temperature 

range. 

All analytical and design efforts, carried on the specimen and on a 

dedicated test facility, converged eventually to a satisfactory match 

between predictions and measurements, confirming both 

mathematical model reliability and Passive Cooler high performance. 

C2-I-04 Mid InfraRed Instrument (MIRI) Cooler 

Subsystem Prototype Demonstration 

D. Durand, R. Colbert, C. Jaco, M. Michaelian, T. 

Nguyen, M. Petach, J. Raab, , Northrop Grumman. 

The Cooler Subsystem for the Mid InfRared Instrument (MIRI) of the 

James Webb Space Telescope (JWST) features a 6 Kelvin Joule- 

Thomson (JT) cooler pre-cooled by a three-stage Pulse Tube (PT) 

cryocooler to provide 65 mW of cooling at the instrument. MIRI’s 6 

Kelvin cooling load, directly behind the primary mirror of JWST, is 

remote from the location of the compressors and pre-cooler. This 

distance, and the parasitic heat load on the refrigerant lines spanning 

it, is accommodated by the design. The effort during 2006 has 

focused on the demonstration of a MIRI Cooler prototype in the 

relevant environment, required to achieve Technology Readiness 

Level 6 (TRL 6) as defined by NASA. Performance when exposed to 

key aspects of the relevant environment, launch vibration and 

simulated thermal-vacuum during operation, will be discussed. 

This work is funded by NASA and managed by the California Institute 

of Technology, Jet Propulsion Laboratory. 

C2-I-05 ABI Active Cooler Subsystem 

S.W. Clark, A.L. Hensley, S.R. Farringer, C.L. 

Bornkamp, P.G. Ramsey, ITT Space Systems. 

The Active Cooler Subsystem is responsible for providing cryogenic 

cooling of the focal planes of the Advanced Baseline Imager (ABI) 

instrument. Main components include primary/redundant two-stage 

pulse tube cryocoolers, flexible thermal straps, vacuum housing 

components and a flexible bellows. 

This paper presents design, analysis, performance and test details of 

the ABI Active Cooler Subsystem. Each cryocooler incorporates an 

integral HEC pulse tube cooler and a remote coaxial cold head that are 

required to provide 2.27W of cooling at 53K and 5.14W of cooling at 

183K. The structural performance of the four unique flexible 

aluminum foil thermal straps range from 0.15 to 5.0 N/mm of 

mechanical flexibility. The thermal conductance requirements of the 

thermal straps are 0.71 W/K @ 53K and 0.37 W/K at 183K. The 

vacuum housing, pseudo-kinematic mounts and related components 

provide structural support for on-orbit environments, survival of 

launch loads, CTE compliance, contamination control and ground 

bench testing. Test data will be included for several components 

including cryocooler vibration, cryocooler off-state thermal loads and 

thermal strap conductivity, vibration transmissibility and load 

deflection. 

ITT leads the Advanced Baseline Imager (ABI) team as the prime 

contractor and has overall responsibility for the program 

development effort. ABI is a NASA administered contract. 

C2-I-06 WISE Solid Hydrogen Cryostat Design Overview 

and Build Status 

L. Naes, Lockheed Martin Advanced Technology 

Center; B. Lloyd, Space Dynamics Laboratory; S. 

Schick, Practical Technology Solutions. 

The Wide-Field Infrared Survey Explorer (WISE) is a MIDEX 

mission that is being developed by the Jet Propulsion Laboratory 

(JPL) to address several of NASA’s Astronomical Search of Origins 

(ASO) objectives. The WISE instrument, developed by the Space 

Dynamics Laboratory (SDL), includes a cryogenically-cooled 

telescope operating at < 13K, and four focal plane assemblies, two of 

which operate at 7.8K. Cooling of the instrument is accomplished by 

a dual-stage solid hydrogen cryostat that is developed by the 

Lockheed Martin Advanced Technology Center (LM-ATC). 

This paper provides an overview of the WISE cryostat design and 

thermal support system along with a status of the flight system build. 

C2-K Large Scale Refrigerators and 

Liquefiers - III 

C2-K-01 Mal-distribution in a 20K Helium Refrigeration 

System Heat Exchanger 

J.A Crabtree, Oak Ridge National Laboratory; G.N. 

Gottier, Cryo Technologies. 

The Hydrogen Moderator System at the Spallation Neutron Source 

utilizes a 7.5kW Helium Refrigerator to cool three circulating loops of 

supercritical hydrogen at a nominal temperature of 20K. When this 

system was originally commissioned, it was discovered that the 

refrigerator’s capacity was not stable at design operating conditions. 

Contrary to conventional wisdom, the system appeared to operate 

more stably and sustained a higher capacity at a lower compressor 

suction pressure. When the suction pressure was increased to design 

conditions, the turbine outlet temperature would initially drop but the 

warm and cold end delta T’s would substantially increase. The 

refrigeration capacity, as measured by the commissioning heater, 

would rise with increased suction pressure to a peak and then quickly 

dissipate. A number of common problems were investigated to no 

avail. At the outset, it was assumed that the stable conditions 

observed at the lower suction pressure would allow continuous 

operation at a reduced capacity. When the system was operated for a 

period of three weeks, however, it was discovered that the capacity 

actually slowly degrades with time. This degradation was easily 

documented by tracking the heater power as well as the heat 

exchanger’s ever increasing delta T’s. A number of diagnostic tests 

were performed that ultimately led to a modification of all of the heat 

exchanger’s headers. A summary of the analyses, diagnosis, repair, 

and results are provided. 

C2-K-02 Improvements of helium 

liquefaction/refrigeration plants and applications 

HP. Wilhelm, K-H. Berdais, Th. Ungricht, Linde 

Kryotechnik AG. 

Design features of a new generation of helium liquefiers and 

refrigerators with liquefaction capacities ranging from 30 to 280 l/h 

LHe (respectively refrigeration capacities from 100 to 900 Watt @ 

4.5K) are presented. The new generation shows an increased 

efficiency due to improved turbine and heat exchanger designs. Other 

benefits of the new design are shortened cool-down times, a very 

compact design and better flexibility and process control. The 

modular setup using standardized components covers a wide range of 

applications including refrigeration at different temperature levels or 

simultaneous liquefaction and refrigeration. The presentation will 

highlight the individual improvements in the design. 

During the presentation the influence of certain parameters like power 

requirement and cold box inlet pressure in relation to the liquefaction 

and refrigeration capacities shall be shown and discussed. 



C2-K-03 Evolution of the standard helium liquefier and 

refrigerator range designed by Air Liquide Advanced 

Technology Division, France 

A. Caillaud, S. Crispel, V. Grabié, F. Delcayre, G. 

Aigouy, Air Liquide DTA. 

The standard helium liquefier and refrigerator range, called HELIAL 

and designed by Air Liquide DTA, has recently been upgraded in 

order to improve the efficiency of these machines. Indeed in the multirange 

of markets requiring these cryogenic systems, (international 

laboratories, aerospace applications, synchrotrons, HTS 

applications...), the technological solution has to provide increasingly 

high performances. The new HELIAL Evolution range, equipped with 

very reliable DTA turbo-expanders, will constitute a highly efficient 

product for this wide application field. The optimizations, adaptations 

and results of the HELIAL Evolution series, doubling the performance 

for the same electrical consumption, will be presented. 

C2-K-04 Cryocooler for Air Liquefaction Onboard Large 

Aircraft 

J.J. Breedlove, P.J. Magari, Creare Inc.; G.W. Miller, 

Air Force Research Laboratory. 

Creare has developed a turbo-Brayton cryocooler designed to produce 

approximately 1 kW of refrigeration at 95 K. The cryocooler is 

intended to provide cryogenic cooling to an air separation system 

being developed for the Air Force to produce and store liquid oxygen 

and liquid nitrogen onboard large aircraft. The oxygen will be used 

for high-altitude breathing and medical evacuation operations, while 

the nitrogen will be used to inert the ullage space inside the fuel tanks. 

The cryocooler utilizes gas bearings in the turbomachines for long life 

without maintenance, which is a critical requirement for this 

application. The mass of a flight version of this cryocooler is 

expected to be around 270 kg, while the input power is expected to be 

approximately 25 kW. This paper describes the design and testing of 

the laboratory demonstration cryocooler that was constructed to 

demonstrate the feasibility of the approach. In the future, the 

cryocooler will be integrated and tested with a distillation column 

subsystem. Subsequent testing may also be performed in-flight on an 

Air Force transport aircraft. 

C2-K-05 Process Study of Nominal 2 K Refrigeration 

Recovery 

P.N. Knudsen, V. Ganni, Jefferson Lab. 

There is an increased interest in the nominal 2K helium refrigeration 

systems (below lambda) for test stands at the present time. This paper 

presents the process parameter choices and their influence on the 

system performance of various non-cold compressor configurations. 

This study is intended to facilitate the adoption of this process in 

conjunction with commercially available small 4.5K helium 

refrigerator systems. By way of an introduction, the efficiency of 

some commonly employed (but inefficient) 2 K process 

configurations are analyzed. Then the analyses of three nominal 2K 

refrigeration recovery process configurations utilizing a refrigeration 

recovery heat exchanger are presented. The effect of the process 

parameters, such as flow imbalance, heat exchanger size, supply 

pressure and 4.5K plant injection location are investigated so that the 

conditions yielding the maximum coefficient of performance can be 

determined. 

C2-K-06 Recent progress in dynamic process simulations 

of cryogenic refrigerators 

A. Kuendig, Linde Kryotechnik AG. 

At the CEC 2005 a paper with the title “Helium refrigerator design for 

pulsed heat load in Tokamaks“ was presented. That paper highlighted 

the control requirements for cryogenic refrigerators to cope with the 

expected load variations of future nuclear fusion reactors. First 

dynamic computer simulations have been presented. 

In the mean time, the computer program is enhanced and new series 

of process simulations are available. The new program considers not 

only the heat flows and the temperature variations within the heat 

exchangers, but also the variation of mass flow and pressure drops. 

The heat transfer numbers now are calculated in dependence of the 

flow speed and the gas properties. PI-controllers calculate the 

necessary position of specific valves for maintaining pressures, 

temperatures and the rotation speed of turbines. 

The value of such a program is the tracing of difficult transient 

operating modes in the design phase of a refrigerator. The simulation 

further is helpful for testing control programs in absence of the real 

refrigerator and it enables to find optimal control parameters. Worth 

mentioning that such a program is applicable for the education of 

engineers and operators. 

C2-K-07 Design of Subcooled Pressurized Cryogenic 

Systems 

G.E. McIntosh, Cryogenic Technical Services, Inc.. 

High temperature superconducting power lines and various beamline 

targets require cooling with subcooled, non-boiling cryogens in the 

pressure range from 5 to 15 Bar. In conventional closed-loop 

refrigerated systems this is accomplished by using a pressurized 

ballast cryogen dewar to maintain the desired pressure. Although 

consumption is modest, cryogen flows continuously from the ballast 

dewar and periodic replenishment is necessary. This paper describes 

an innovative refrigerated system which eliminates the ballast dewar 

and operates continuously without cryogen or gaseous make-up after 

the initial fill. 

C2-K-08 The Cost of Helium Refrigerators and Coolers 

for Superconducting Devices as a Function of Cooling 

Power at 4.5 K 

M. A, Green, Lawrence Berkeley National 

Laboratory. 

This paper is written in memory of Rod Byrns of the Lawrence 

Berkeley National Laboratory who died two years ago. 

This paper is an update of papers written in 1991, 1997 by Rod Byrns 

and this author concerning estimating the cost of refrigeration for 

superconducting magnets and cavities. The actual costs of helium 

refrigerators and coolers (escalated to 2007 dollars) are plotted and 

compared to a correlation function. A correlation function between 

cost and refrigeration at 4.5 K and 1.8 K is given. The capital cost of 

larger refrigerators (greater than 50 W at 4.5 K) 1s plotted as a 

function of 4.5 K cooling. The cost of small coolers is also plotted as 

a function of refrigeration available at 4.5 K. An annual cost for 

refrigeration can also be estimated based on the refrigeration at 4.5 K 

or 1.8 K and the cost of electrical energy. A correlation function for 

estimating input power to the compressors to the refrigeration 

produced at 4.5 K and 1.8 K is also given. 

This work was supported by the Office of Science, United States 

Department of Energy, under DOE contract DE-AC02- 

05CH11231. 

C2-L Stirling and Pulse Tube Coolers, 

Development and Testing (Aerospace) 

C2-L-01 Development Of A 4.5 K Pulse Tube Cryocooler 

For Superconducting Electronics 

Ted Nast , Jeff Olson , Patrick Champagne , Jack 

Mix, Bobby Evtimov, Eric Roth , Andre Collaco , , 

Lockheed Martin Space Co. 

Lockheed Martin`s Advanced Technology Center is developing a four 

stage pulse tube to provide temperatures of 4.5 K for superconducting 

electronics to be used in a ground based communications system. We 

have developed prior 4 stage units which have operated down to 3.8K. 

The relatively high cooling loads for this program led us to a design 

which reduces the input power over prior systems. The design of the 

system includes a unique pulse tube approach using both Helium-3 

and Helium 4 working gas in two separate compression spaces, which 

leads to enhanced power efficiency. The compressor is our standard 

moving magnet, clearance seal, flexure bearing system. This paper 

will present the experimental data and compare it with our prediction 

methods. 

The system is compact, lightweight and reliable and utilizes our 

aerospace cooler technology to provide unlimited lifetime. The unit is 

an engineering model to demonstrate proof of concept. Follow on 

production for ground based communication systems is anticipated. 

This work is subcontracted from HYPRES and is funded by the Army 

and the Navy 



C2-L-02 Development and Space Flight Qualification of a 

Dual Stage 20K Stirling Cryocooler 

M.G. Houston, M. Brownhill, J.S. Reed, A.S. Gibson, 

EADS Astrium Limited. 

A two-stage Stirling cycle cooler has been developed for space 

applications to provide cooling below 20K. It was initially developed 

for the ESA Far Infrared Space Telescope (FIRST). The FIRST 20K 

cooler is the first dual-stage Stirling cryocooler to be developed under 

funding by ESA and has successfully passed a qualification readiness 

review in 2006. 

The qualification model cooler has a 2-stage displacer with a helium 

working gas, compressed by dual-opposed pistons, and implements a 

momentum balancer unit attached to the displacer, to achieve low 

vibration characteristics for the system. This cooler builds on the 

success and heritage of the Astrium 50-80K Stirling cryocooler 

mechanisms. The cooler benefits from unparalleled space heritage, 

with a capability for high efficiency at low temperatures and ability to 

lift heat at 2 different temperatures. It is capable of providing in 

excess of 120mW heat lift at 20K at the cold stage, while providing 

500mW heat lift at the mid-stage for an input power of


C2-M Instrumentation 

C2-M-01 Operation of Superconducting Digital Receiver 

Circuits on 2-Stage Gifford-McMahon Cryocooler 

R.J. Webber, V. Dotsenko, A. Talalaevskii, R. Miller, 

J. Tang, D. Kirichenko, I. Vernik, P. Schevchenko, D. 

Gupta, O.A. Mukhanov, Hypres, Inc. 

We have demonstrated the full operation of digital RF receivers on a 

Hypres-designed cryostat, which couples a Nb-based superconducting 

Rapid Single Flux Quantum (RSFQ) chip to a commercially available 

100 mW 4 Kelvin Gifford-McMahon cryocooler. The electrical 

performance at clock speeds in excess of 24 GHz is described as well 

as the design of the electrical interfaces with room temperature 

support electronics. The digital receiver chip is a 1cm x 1 cm chip 

comprising ~ 11,000 Josephson junctions. Within the cryostat there is 

the inevitable conflict between the need to minimize heat-leaks and 

the need to minimize dissipation in input-output leads. The measured 

cryogenic thermal and magnetic environments of the chip are 

discussed and their impact on performance. Reception and direct 

digital conversion of real signals in the HF-, VHF-, and X-bands 

including signals from military satellite antennae shows the potential 

of this system to replace large and power-hungry multiple analogue 

receivers. 

This work was supported in part by the Office of Naval Research, the 

Army Small Business Innovation and Research Program and by the 

US Air Force 

C2-M-02 Level-detected characteristics of MgB2 sensor 

for liquid hydrogen 

M. Takeda, T. Akazawa, Y. Iwamoto, Kobe 

University; H. Kumakura, A. Matsumoto, H. Uematsu, 

C. Kazama, National Institute for Materials Science; 

H. Iwashita, I. Kodama, Y. Matsuno, Iwatani 

Industrial Gases Corporation. 

In order to establish the storage and transportation system for liquid 

hydrogen, it is important to develop a high sensitive liquid level 

meter. A superconductive MgB2 level meter is expected to be a new 

one. However, a research on the level-detected characteristics of the 

MgB2 sensor has not been sufficiently carried out. Thus the 

characteristics of the level sensor, which consists of a MgB2 wire (0.5 

mm in diameter, 200 mm long) made by means of powder-in-tube 

method, an electrical heater, and voltage/current taps, were 

investigated by using the liquid hydrogen optical cryostat. The 

linearity, resolution, repeatability, and heater current dependence of 

the sensor reading with varying liquid levels are discussed. 

This work was supported in part by Hyogo Prefecture (COE 

Program), Japan. 

C2-M-03 Cryogenic Fiber Optic Sensors Based on Fiber 

Bragg Gratings 

P.R. Swinehart, M. Maklad, S.S. Courts, Lake Shore 

Cryotronics, Inc. 

Fiber optic sensing has many favorable characteristics - a single fiber 

can be used to interrogate multiple sensors along the length of the 

fiber, fiber optic sensing is immune to electromagnetic noise and is 

inherently safe for combustible liquids and atmospheres. Previously, 

fiber optic sensors based on fiber Bragg gratings (FBGs) have been 

demonstrated for cryogenic use for both temperature and strain 

sensing, but often little data is supplied as to the reproducibility or 

unit-to-unit uniformity of these sensors. Lake Shore Cryotronics has 

manufactured fiber optic cryogenic temperature and strain sensors 

based on Bragg gratings using novel packaging techniques. The 

reproducibility and uniformity characteristics of the cryogenic strain 

sensor is reported for 295 K and 77K. The temperature response, 

reproducibility, and uniformity of wide range temperature sensors is 

reported from 20K to 480K. 

C2-M-04 A Commercial Ruthenium Oxide Thermometer 

For Use to 10 mK 

S.S. Courts, J.K. Krause, Lake Shore Cryotronics, Inc. 

The adoption of the PLTS-2000 has given the ultra low temperature 

community a recognized temperature scale with which to work. 

However, the defining instrument, the He-3 melting curve 

thermometer, is not well suited for transferring this scale. Primary 

thermometers are available for ultra low temperatures, namely nuclear 

orientation and noise thermometry, but they are statistical in nature 

and require long averaging times for a single measurement limiting 

their practical use. Resistance thermometers are easy to use, provide 

fast measurements allowing active feedback temperature control, and 

have extremely high sensitivities at ultra low temperatures allowing 

for microkelvin level control. However, resistance thermometry for 

use below 50 mK requires rethinking the standard packaging. Many 

common materials used in packaging cryogenic sensors limit the 

thermal connection to the sensor thus limiting the allowable excitation 

used for measurement. This research examines the use of a 

commercially available ruthenium oxide thick film chip resistor for 

thermometry to 10 mK. Data was acquired for sample sensors 

fabricated using two package styles. The temperature was measured 

using a Co-60 nuclear orientation thermometer in conjunction with 

PTB-calibrated germanium thermometers. Resistance as a function of 

temperature, self-heating and time response data are presented. 

C2-M-05 The Effect of Small Helium Leaks into Low 

Temperature Systems 

J. Panek, E. Canavan, M. DiPirro, J. Francis, S. 

Riall, P. Shirron, NASA. 

Recent experience with small helium leaks (


Wednesday, 07/18/07 Poster 

3:30pm - 5:00pm 

C2-O Instrumentation - Large Scale Systems 

C2-O-01 First Experience with the LHC Cryogenic 

Instrumentation 

N. Vauthier, Ch. Balle, J. Casas-Cubillos, G. 

Fernandez-Penacoba, E. Fortescue-Beck, P. Gomes, 

N. Jeanmonod, A. Lopez Lorente, A. Suraci, CERN. 

The LHC under construction at CERN will be the world’s largest 

super-conducting accelerator and therefore makes massive use of 

cryogenic instruments. The cryogenic instrumentation mainly 

comprises sensors for temperature, pressure and level, as well as 

heaters and valve actuators. These instruments are installed in the 

tunnel and therefore have to withstand the LHC environment that 

imposes radiation-tolerant design and construction. Most of the 

instruments require individual calibration; some of them exhibit 

several variants as concerns measuring span; all relevant data are 

therefore stored in an Oracle® database. Those data are used for the 

various quality assurance procedures defined for installation and 

commissioning, as well as for generating tables used by the control 

system to configure automatically the input/output channels. This 

paper describes the commissioning of the sensors and the 

corresponding electronics, the first measurement results during the 

cool-down of one machine sector; it discusses topics that caused 

problems and the solutions found. Furthermore it also gives an 

overview of the different procedures covering final installation stages, 

testing and cool-down operations. 

C2-O-02 Calibration of Cryogenic Thermometers for the 

LHC 

Chr. Balle, J. Casas-Cubillos, N. Vauthier, CERN; 

J.P. Thermeau, IPN, Orsay. 

7000 cryogenic temperature sensors of semi-conductor type covering 

the range from room temperature down to 1.6 K are installed on the 

LHC machine under construction. In order to meet the stringent 

requirements on temperature control of the super-conducting magnets, 

each single sensor needs to be calibrated individually. In the 

framework of a special contribution, IPN (Institut de Physique 

Nucléaire) in Orsay, France built up and operated a calibration facility 

with a throughput of 80 thermometers per week. 

After reception from the manufacturer, the thermometer is assembled 

onto a support specific to the measurement environment, thermally 

cycled ten times and calibrated at least once from 1.6 to 300 K. The 

procedure for each of these interventions includes various 

measurements and the acquired data is recorded in an ORACLE®database. 

Furthermore random calibrations on some samples are 

executed at CERN to crosscheck the coherence between the 

approximation data obtained by both IPN and CERN. In the range of 

1.5 K to 30 K, the calibration apparatuses at IPN and CERN are 

traceable to standards maintained in a national metrological laboratory 

by using a set of rhodium-iron temperature sensors of metrological 

quality. 

This paper presents the calibration procedure, the quality assurance 

applied, the results of the calibration campaigns and the return of 

experience gained. 

C2-O-03 Radiation Requirements and Testing of 

Cryogenic Thermometers for the ILC 

J. Trenikhina, Saratov State University; T. Barnett, 

University of Illinois; Yu.P. Filippov, Joint Institute 

for Nuclear Research; N. Mokhov, N. Nakao, A. 

Klebaner, K. Vaziri, Fermi National Accelerator 

Laboratory*; S. Korenev, J.C. Theilacker, Beams & 

Plasma Technologies. 

Large quantity of cryogenic temperature sensors will be used for 

operation of the International Linear Collider (ILC). Most of them 

will be subject to high radiation doses during the accelerator lifetime. 

Understanding of particle energy spectra, accumulated radiation dose 

in thermometers and its impact on performance are vital in 

establishing technical specification of cryogenic thermometry for the 

ILC. Realistic MARS15 computer simulations were performed to 

understand the ILC radiation environment. Simulation results were 

used to establish radiation dose requirements for commercially 

available cryogenic thermometers. Two types of thermometers, 

Cernox® and TVO, were calibrated prior to irradiation using different 

technique. The sensors were subjected then to up to 200 kGy electron 

beam irradiation with kinetic energy of 5 MeV, a representative of the 

situation at the ILC operation. A post-irradiation behavior of the 

sensors was studied. The paper describes the MARS15 model, 

simulation results, cryogenic test set-up, irradiation tests, and 

cryogenic test results. 

*Work supported by the U.S. Department of Energy under contract 

No. DE-AC02-76CHO3000. 

C2-O-04 Instrumentation, data acquisition and controls 

for temperature measurement of cold surfaces at 4.5 K 

and 80 K of SST-1 machine 

P. Panchal, D. Sonara, B. Sarkar, R. Bhattacharya, R. 

Panchal, R. Patel, J. Tank, M Singh, A.K. Sahu, Y.C. 

Saxena, Institute for Plasma Research. 

Two-temperature regimes have been envisaged for the SST-1 

machine, 80 K on the thermal shield and 4.5 K of the superconducting 

magnet system. The aim of temperature measurement is two folds (i) 

to monitor the temperature distribution as well as process parameters 

(ii) to achieve controlled cool down from 300 K to 4.5 K and 80 K. 

Temperature sensors have been mounted on cold surfaces at strategic 

locations to ease the operation during cool down and steady state. 

Several techniques are employed for temperature measurement and 

control. Cernox sensors (Lakeshore make) and PT -102 have been 

used for the temperature measurement at 4.5 K and 80 K surfaces 

respectively. A data acquisition system (DAS) has been indigenously 

developed using 4-20 mA current loop transmitter, which provided 

better functioning than the commercially available one. The reliability 

of the transmitter card has been tested on-line for continuous 

operation for 3 months. The control functioning has been designed 

and developed using programmable logic controller with built-in 

support for calibration curve handling, failure alarm and 3-port 

isolation with direct interfacing of the transmitter card. The 

temperature data is obtained at the supervisory control and data 

acquisition of dedicated node. The developed DAS has been found to 

be very reliable and satisfactory. The paper will describe the details of 

the philosophy of the DAS and experience along with indigenously 

developed transmitter card. 



C2-O-05 Thermal and electrical anchorage of 

superconducting devices into large facility 

superconducting magnets. 

B. Minetti, R. Gerbaldo, G. Ghigo, L. Gozzelino, F. 

Laviano, G. Lopardo, E. Mezzetti, R. Cherubini, Dept 

of Physics - Politecnico Torino; A. Rovelli, INFN- 

LNS. 

In this paper the issue of exploiting the use of superconducting 

sensors with their extremely favourable radiation hardness and low 

noise properties at low temperatures is addressed with reference to 

other currently used sensor solutions. The major problem for an 

extensive use of superconductors as field and photon sensors was 

(until now) referred to the need of the sensors anchorage to cold 

fingers in cryocoolers. In large facilities such as e.g. LHC (CERN) 

environment, running at temperature lower then 4K, the problem is 

reduced to achieving technical solutions for thermal anchorage, 

shielded read-outs and space constraints. In the paper several solution 

are proposed on the basis of measurements and suitable tests in 

controlled ambient at the large I.N.F.N. irradiation facilities in LNL, 

(Legnaro- Padova, Italy) and LNS (Catania, Italy). 

C2-O-06 Cryogenic Controls System for Fermilab’s SRF 

Cavities Test Facility 

B. Norris, R. Bossert, A. Klebaner, S. Lackey, A. 

Martinez, L. Pei, W. Soyars, V. Sirotenko, Fermi 

National Accelerator Laboratory. 

A new superconducting radio frequency (SRF) cavities test facility is 

now operational at Fermilab’s Meson Detector Building (MDB). The 

facility is supplied cryogens from the Cryogenic Test Facility (CTF) 

located in a separate building 500 m away. The design incorporates 

ambient temperature pumping for super-fluid helium production, as 

well as three 0.6kW at 4.5K refrigerators, five screw compressors, a 

helium purifier, helium and nitrogen inventory, cryogenic distribution 

system, and a variety of test cryostats. To control and monitor the 

vastly distributed cryogenic system, a flexible scheme has been 

developed. Both commercial and experimental physics tools are used. 

APACS+, a process automation control system from Siemens-Moore, 

is at the heart of the design. APACS+ allows engineers to configure 

an ever evolving test facility while maintaining control over the plant 

and distribution system. APACS+ nodes at CTF and MDB are 

coupled by a fiber optic network. DirectLogic205 PLC’s by KOYO 

are used as the field level interface to most I/O. The top layer of this 

system uses EPICS (Experimental Physics and Industrial Control 

System) as a SCADA/HMI. Utilities for graphical display, control 

loop setting, real time/historical plotting and alarming have been 

implemented by using the world-wide library of applications for 

EPICS. OPC client/server technology is used to bridge across each 

different platform. 

This paper presents this design and its successful implementation. 

C2-O-07 The assembly of the LHC Short Straight 

Sections cryostats at CERN: work organization, Quality 

Assurance and lessons learned. 

V. Parma, N. Bourcey, P. Campos, R. Lopez, A. 

Poncet, CERN. 

After 4 years of activity, the assembly of the approximately 500 Short 

Straight Sections (SSS) for the LHC has come to an end at the 

beginning of 2007. This activity, which was initially foreseen in 

European industry, was in-sourced at CERN because of the 

insolvency of the prime contractor. While the quadrupole cold masses 

were produced in industry, the assembly within their cryostats was 

transferred to CERN and executed by an external company under a 

result-oriented contract. CERN procured cryostat components, set up 

a dedicated 2000 m2 assembly hall with all the specific assembly 

equipment and tooling and defined the assembly and testing 

procedures. The contractor took up responsibility for the timely 

execution within the required quality. A dedicated CERN production 

and quality assurance team was constituted. A specific quality 

assurance plan was set up involving 2 additional contractors 

responsible for weld inspections (more than 5 km of critical assembly 

welds) and the execution of about 2500 leak detection tests. 

This paper presents the organizational aspects of the activity and the 

experience gained throughout the production. The learning curves and 

statistics by type of non-conformities detected and general quality 

assurance aspects are presented and discussed. The main lessons 

learnt are summarized, in an attempt to draw some conclusions and 

guidelines which could be useful in making strategic choices for the 

cryostat assembly in future large-scale accelerators. 

C2-P High Temperature Superconducting 

Devices 

C2-P-01 Numerical Simulation of Pulsed Field 

Magnetization of Cryocooler-Cooled Bulk 

Superconductor 

Hiroyuki Ohsaki, Sousuke Matsumura, Satoshi 

Kawamoto, Ryosuke Shiraishi, The University of 

Tokyo. 

RE-Ba-Cu-O bulk superconductors have strong flux pinning force and 

are expected to be used as a strong magnetic flux source. 

Magnetization is a very important technique to be studied for such 

application of bulk superconductors. In particular, pulsed field 

magnetization (PFM) is considered a useful method for magnetizing 

bulk superconductor because this method needs a more compact fieldexcitation 

system than the field cooling magnetization (FCM). Multipulse 

techniques have been also investigated experimentally for PFM 

to reach as high a trapped magnetic field as that obtained by FCM. 

Numerical analysis techniques are also quite important to perform 

such research subjects more effectively and clarify the physical 

phenomena. 

We have studied the pulsed field magnetization of cryocooler-cooled 

bulk superconductor. A simulation tool based on the finite element 

method has been developed, and transient phenomena in 

electromagnetic and thermal conduction fields during pulsed field 

magnetization were analyzed. Bulk superconductor was modeled 

using an E-J relation based on a power law. Dependence of critical 

current density on flux density and temperature was taken into 

account. Approximate modeling of thermal conductivities and electric 

properties of the system components was carried out. The relation 

between PFM conditions and trapped magnetic field is discussed. 

C2-P-02 Persistent magnetization of MgB2 cylinders 

induced by a pulsed field 

G. Giunchi, E. Perini, EDISON SpA; T. Cavallin, 

CNR-IENI; R. Quarantiello, V. Cavaliere, A. Matrone, 

ANSALDO CRIS. 

High stable trapped fields in bulk superconductors can be useful 

applied in many electrotechnical applications. The HTS bulk materials 

can be magnetized applying constant magnetic fields or pulsed 

magnetization methods. Even if the pulse magnetization is far less 

effective than the DC magnetization in the trapping ability, it appears 

as the most friendly technique in practical devices. So we have studied 

the effects of the pulsed technique, applied to bulk MgB2 cylinders 

that are very promising devices in view of their easy manufacturing in 

large dimensions [1]. To this purpose we have used a copper solenoid 

to magnetize the MgB2 cylinder, both cylinder and solenoid 

conductively cooled between 10 and 25 K. This simple cryogenic 

arrangement can be representative of many more elaborate practical 

devices. Tailoring the applied pulsed field and the sequence repetition, 

we successfully magnetize cylinders of diameter of the order of 50 

mm, to more that 0.5 T, in their centre, and the persistent 

magnetization is not affected by external perturbations. The 

parameters which regulate the trapping field performances are mainly 

related to the heat management of the MgB2 cylinder. This aspects is 

discussed and modelled with numerical computations and several 

assembling solutions of the magnetized cylinders are presented. 

[1] G.Giunchi et al., Cryogenics 46, 237-242 (2006) 



C2-P-04 Cryogenic design of the ALUHEAT project 

I. Hiltunen, A. Korpela, R. Mikkonen, J. Lehtonen, 

Tampere University of Technology; M. Runde, 

SINTEF Energy Research; N. Magnusson, SINTEF 

Energy Research ; G. Kalkowski, Fraunhofer IOF. 

In this paper, the cryostat design of the ALUHEAT project that aims 

to build a cryogen-free superconducting induction heater is presented 

in detail. Designing of the cryostat involves heat loss calculations, 

mechanical analysis and the optimization of current leads and cooling 

conditions. The system consists of two separate cryostats between of 

which the billet to be heated is located. Exceptionally short distance 

between the magnet and the cryostat wall, the large forces between the 

magnets in separate cryostats, and the rotation of the billet create 

application specific requirements that must be taken into account. 

Finite element analysis is used to design the cryostat to withstand both 

the vacuum and magnetic forces. 

Finally, the thermal interface, the radiation shield and the magnet 

support are designed and all components assembled into the complete 

system. 

C2-P-05 Introduction of the 35kV/90MVA Saturated Iron 

Core Type Superconducting Fault Current Limiter 

Y. Xin, W.Z. Gong, X.Y. Niu, B. Tian, Z.J. Cao, H.X. 

Xi, Y. Yang, J.Y. Zhang, X,M. Hu, H. Hong, A.L. Ren, 

Z.L. Chen, H.H. Li, B. Hou, X.C. Yang, Innopower 

Superconductor Cable Co.. 

A 35kV/90MVA prototype saturated iron core type superconducting 

fault current limiter was developed and installed in a transmission 

network for testing and trial operation. This prototype is of many 

unique features, such as actively de-magnetizing the iron core when a 

fault takes place to enhance the limiting capacity, additional circuit for 

protecting the dc current supply and other components in the dc bias 

side, and a new concept in iron core design. These innovations 

overcome the shortcomings that the long-established design of a 

saturated iron core type superconducting fault current limiting device 

has, making this type of current limiter more reliable and efficient. 

For the 35kV/90MVA system, we plan to carry out a live-grid trial 

operation at Puji Substation of China Southern Power Grid for a long 

period of time. In this presentation, we will report the technical 

details of the system and the testing results we have got up to date. 

C2-P-06 Modular concept for the cryopackaging design. 

V.V. Borzenets, SLAC; I.V. Borzenets, Duke Univ. 

Cryocooled devices and assemblies always involve two interfaces: the 

cryogenic interface which provides the required low temperatures, and 

the electronic interface which essentially provides the function of your 

device. A problem with all current systems is that these two interfaces 

are linked together. That means that in order to do any component 

replacement or electronics maintenance, the entire system has to be 

shut down and taken apart. This introduces extensive delays during 

system assembly and usage. More over, this rules out a system with 

easily interchangeable electronic components. 

We propose a concept of modular packaging that will completely 

decouple the cryogenic/temperature control interface with the 

electronic interface. This will result in the ability to quickly remove 

and replace one interface without the need to shut down or 

disassemble the other. This means that the system will not only have 

reduced servicing time, but that the system will have the capability to 

do “cold swaps”. Conceptually, this would be achieved by having a 

separate vacuum space for the cryogenic interface as well as for each 

detachable electronic interface block. The thermal contact for all low 

temperature stages of the cryocooler with the electronics package will 

be achieved via properly matched thermal metal to metal contacts. 


5:00pm - 6:00pm 

C2-R JT Coolers (Non-Aerospace) 

C2-R-01 Fast Cool-Down J-T Cryocooler to 88K 

N. Tzabar, I. Lifshits, A. Kaplansky, Rafael Ltd.. 

Fast cool-down is usually implemented with J-T cryocoolers which 

also enable low-cost and small-scale systems. In this paper, we 

describe an analysis for achieving cool-down time of a few seconds to 

88K, using Argon as the main coolant, and at least 3 minutes of steady 

state cooling. It appears that according to system demands, cost 

reduction, reliability, and manufacturing considerations the use of 

Argon as a single coolant is more beneficial than precooling with 

another coolant, such as Krypton. The results were successfully 

verified against experimental data. 

C2-R-02 Vibration Characterization and Reduction of a 

Joule-Thomson Cryocooler for a SQUID-Based Metal 

Detection System 

G.J. De Groot, CSIRO Industrial Physics, M.A. 

SANTIN, CSIRO Industrial Physics & Federal 

University of Santa Catarina, T. THIJSSEN, CSIRO 

Industrial Physics & University of Twente. 

Very sensitive high-temperature SQUID (Superconducting Quantum 

Interference Device) magnetometers are used for the detection of very 

small metal contaminants in food and other products. When the 

SQUIDs are cooled with liquid nitrogen, a detection sensitivity of 500 

nAm2 in a 150 × 150 mm2 orifice is obtained [1]. However, when a 

commercial Joule-Thompson cryocooler was used, the sensitivity was 

reduced by a factor of 5 due to spurious magnetic signals [2]. 

In this study the emphasis is on understanding noise that may be 

created due to mechanical vibrations in the cryocooler cold head. The 

natural frequencies of the cryocooler cold head are modelled and two 

mechanisms of noise generation are considered and analysed. 

Calculations show that the noise created by vibrating dipoles in the 

cold head may create noise of 1 pT up to 20 pT in the frequency range 

of 10 to 50 Hz. The vibration characteristics of several parts of the 

cryocooler cold head assembly were determined with a laser 

vibrometer, a fluxgate magnetometer and through finite element 

simulations. Two natural frequencies of approximately 21 and 49 Hz 

are particularly noticeable and are also observed in the SQUID noise. 

Anti-vibration measures are introduced to reduce external vibrations. 

Many thanks go out to Marcel Bick, David Tilbrook, Keith Leslie, 

Barry Martin, Lawrence Dickinson, Prem Narang and Emma Mitchell 

for their support and insights. 

C2-R-03 Performance of a precooled J-T refrigerator 

operating with refrigerant mixtures 

C.T. Sairam, G. Venkatarathnam, Indian Institute of 

Technology Madras. 

Single stage J-T refrigerators operating with refrigerant mixtures are 

under development worldwide. Precooled J-T refrigerators operating 

with refrigerant mixtures were studies by Alexeev et.al for operation 

in 90-100 K temperature range [1-2]. 

In this paper we present the results obtained by us in a two stage J-T 

refrigerator. Mixtures of propane and ethane are used in the first stage, 

and mixtures of neon,nitrogen,methane, ethane and propane in the 

second stage. The refrigerator was tested in the temperature range 69- 

85 K. A heat load of 9W was met at a temperature of 77K with a 

power input of 1.4 kW. A heat load of 50W was met at a temperature 

of 100K with a power input of 1.1-1.3 kW. The performance of the 

refrigerator with different mixtures in the precooling stage and the 

main stage are described in this paper. 

References 

1.Alexeev, A., Ch. Haberstroh and H. Quack (1998) Further 

development of a mixed gas Joule-Thomson refrigerator. Advances in 

Cryogenic Engineering, 43B, 1667-1675. 

2.Alexeev, A., Ch. Haberstroh and H. Quack (1999) Mixed Gas J-T 

Cryocooler with Precooling stage. Cryocoolers 10, 475-479. 



C2-R-04 Open cycle Joule-Thomson cryocooling with 

prior sequential isentropic expansion 

B-Z. Maytal, Rafael. 

The high pressure stream outlets a gas reservoir and expands through 

a loaded turbine prior to being fed into a Joule-Thomson (J-T) 

cryocooler. Due to the load and according to its extent, the gas drops 

its pressure through the turbine at a constant entropy process. On the 

one hand, the gas that inlets the J-T cryocooler is of lower pressure 

than without a turbine. This effect suppresses the integral isothermal 

J-T effect which is the specific cooling capacity of the stream. On the 

other hand, the isentropic expansion is accompanied by temperature 

reduction which elevates the specific cooling capacity. This effect 

dominates the former one thus consequently; the specific cooling 

capacity is enhanced even when the high pressure gas reservoir stays 

isothermal. The isentropic expansion is always accompanied by a 

temperature drop which is quite substantial. Therefore, the expanded 

very first cooled stream inletting the J-T cryocooler may significantly 

accelerates the cooldown process.. This beneficial performance of the 

serial arrangement of a turbine and a J-T cryocooler is analyzed and 

formulated for argon and nitrogen according to any loading policy as 

for instance, dropping the pressure at the turbine by a predetermined 

constant factor. 

C2-S Superconducting Cables 

C2-S_01 The Latest Status of A Long Term In-grid 

Operation in Albany HTS Cable Project 

H. Yumura, T. Masuda, M. Watanabe, H. Takigawa, 

Y. Ashibe, H. Ito, M. Hirose, K. Sato, Sumitomo 

Electric, Industries, Ltd. 

The HTS cable system is expected to be a solution for improvement of 

the power grid, and three demonstration projects in the real grid have 

been carrying out in the United States. The Albany Cable Project, one 

of them, is to develop the 350 meters long HTS cable system with 

capacity of 34.5kV, 800A, connecting between two substations in 

National Grid Power Company`s grid. 

A 320-meter and a 30-meter cable are installed into underground 

conduit and jointed each other at a vault. The cable was fabricated 

with Di-BSCCO wire total amount of 70km and has the structure of 3 

cores-in-one cryostat. The cable installation of a 320-meter and a 30- 

meter section was completed successfully with using the same pulling 

method of a conventional cable. After cable installation, the joint and 

two terminations were assembled at the test site. After the initial 

cooling of the system, the completion tests such as the critical current, 

heat loss measurement and DC withstand voltage test were conducted 

successfully. 

The in-grid operation was begun on 20th of July, 2006. And a long 

term in-gird operation has been progressed satisfactorily at unattended 

condition. In the Albany project, the 30-meter section is planed to be 

replaced to YBCO cable in this spring. The development of YBCO 

cable has been carried out by using SuperPower’s YBCO coated 

conductors. This paper describes the latest status of the Albany cable 

project. 

C2-S-02 Deveopment of YBCO Cable for Albany HTS 

Cable Project 

H. Yumura, M. Ohya, Y. Ashibe, H. Ito, T. Masuda, K. 

Sato, Sumitomo Electric Industries, Ltd. 

The Albany Cable Project is to develop the 350 meters long HTS 

cable system with capacity of 34.5kV, 800A, connecting between two 

substations in National Grid Power Company`s grid. 

In-grid operation with BSCCO HTS cable was begun on 20th of July, 

2006, successfully. And a long term in-gird operation has been 

progressed satisfactorily at unattended condition. The BSCCO cable 

line consists of a 320-meter, a 30-meter cable, cable-to-cable splice in 

vault and two terminations. In the Albany project, the 30-meter 

section is planed to be replaced to YBCO cable in this spring. The 

development of YBCO cable has been carried out by using 

SuperPower’s YBCO coated conductors. The YBCO sample core was 

fabricated and evaluated its electrical and mechanical properties in 

order to confirm the cable design. The critical current of conductor 

and shield were approx. 1.4 kA and 2.0 kA, respectively. They are 

almost same as design value considering with tape’s Ic and the effect 

of magnetic field. The ac loss of the sample was 0.4 W/m/ph at 800 

Arms of 60Hz. The fault current test, 23kA and38cycles, was 

conducted under open bath condition. The temperature rises at 

conductor and shield were almost same as the ones of BSCCO core, 

and no Ic degradation was found after the fault current test. This paper 

describes the detail of test results for YBCO sample core and design 

of YBCO cable for Albany Project. 

C2-S-03 A Cooling System for Navy Degaussing Cables 

J. Yuan, J. Maguire, D. Aized, A. Covel, American 

Superconductor Co. 

Degaussing cables are a vital part of today’s military ships. 

Degaussing cables are utilized in most navy ships to reduce their 

magnetic signature, thereby making them much more difficult to be 

“seen” by magnetic sensors and by magnetically activated mines. 

Current degaussing systems consist of a series of field-generating 

loops and their installation involves running heavy copper cables 

around the perimeter of the ship’s hull. High Temperature 

superconductor-based degaussing cables provide many benefits as a 

replacement for conventional, copper-based degaussing systems, 

including lighter weight, lower operating voltage, lower installation 

costs, higher energy efficiency and smaller size. In March 2006, 

AMSC announced that it had demonstrated the successful operation of 

the world’s first full-scale HTS degaussing cable for military ships. 

The 40 meter long HTS degaussing cable produced 4100 Amp-turns 

with a significant decrease in operating voltage to less than 0.5 volts, 

or 1000 times lower than a comparable Amp-turn copper-based 

system. The system has been continuing running since March, 2006. 

This paper reviews the testing of the degaussing cable, along with a 

comparison between the simulation and experiments. 

C2-S-04 Performance Test of Cooling System for KEPCO 

HTS Power Cable 

H.S. Yang, D.L. Kim, B.S. Lee, Y.S. Choi, Korea Basic 

Science Institute; S.H. Sohn, J.H. Lim, Korea Electric 

Power Research Institute; H.S. Ryoo, S.D. Hwang, 

Korea Electrotechnology Research Institute. 

A cooling system for a 3-phase 100m HTS power cable with 

22.9kV/1.25kA was installed and tested at KEPCO’s Gochang power 

testing center in Korea. The system consists of a liquid nitrogen 

decompression cooling system with a cooling capacity of 3kW at 66K 

and a closed circulation system of subcooled liquid nitrogen. Several 

performance tests of the cable system with respect to the cooling such 

as heat load, AC loss and temperature stability, were performed at 

operating temperature of 66.4K. Thermal cycle test, cool-down to 

liquid nitrogen temperature and warm-up to room temperature, was 

also performed to investigate thermal cycle influences. The outline of 

the installed cooling system and performance test results are presented 

in this paper. 

This research was supported in part by the Electric Power Industry 

Technology Evaluation & Planning office, Republic of Korea. 



C2-T Thermoacoustics 

C2-T-01 A thermoacoustically-driven two-stage pulse 

tube cryocooler operating below 20K by using a novel 

coupler 

J.Y. Hu, Graduate University of Chinese Academy of 


Chemistry, CAS; W. Dai, Technical Institute of 


In a heat-driven thermoacoustic cryocooler, the optimum working 

frequency of the pulse tube cooler is often below 50Hz and the 

pressure ratio is higher than 1.2. Meanwhile a typical thermoacoustic 

heat engine with moderate dimensions often can not meet the need of 

the cooler. So in our new heat-driven thermoacoustic cryocooler, a 

new coupling method was employed to decrease the frequency and 

improve the pressure ratio. First, a tube with a reservoir was used as 

an acoustic amplifier to connect the engine and the cooler. The 

acoustic amplifier can amplify the amplitude of pressure wave 

through it, and this allows the cooler to obtain higher pressure ratio 

than that in the engine itself. Secondly, an acoustic transparent but gas 

blocking membrane was installed between the engine and the cooler. 

Thus, the engine can use nitrogen as the working gas to work at low 

frequency; meanwhile, the cooler can still use helium to maintain its 

high refrigeration performance in cryogenic temperature range. 

Because of the new coupling method, the thermoacoustic engine 

worked at about 23.5Hz and the pressure ratio in the pulse tube cooler 

reached 1.27. Consequently, a lowest cooling temperature of the heatdriven 

thermoacoustic cryocooler reached 18.1K. This new heatdriven 

thermoacoustic cryocooler promises good application potential 

for thermoacoustic technology in the temperature of liquid hydrogen. 


China(Grant No.50506031 and No.50625620) 

C2-T-02 Universal scaling law of inertance tube phase 

shifters 

S.L. Zhu, Graduate University of Chinese Academy of 


Chemistry, CAS; Z.H. Wu, W. Dai, Technical Institute 

of Physics and Chemistry,CAS. 

The inertance tube is a long thin tube that is now frequently used as 

phase shifters of pulse tube cryocoolers. However, previous works 

usually focused on specific operating case of an inertance tube, which 

make their conclusion lack of universal guidance for other peoples. 

Thus, developing a universal scaling law of the inertance tube shifter 

becomes the objective of this work. Because different pulse tube 

coolers need different inertance tube phase shifter which can be 

characterized by its acoustical power transmission and phase shifting 

capability. In other word, the acoustical power at the inlet of the 

inertance tube simply reflects the gross cooling capacity of the pulse 

tube cryocooler, and the phase angle at its inlet is required by the 

pulse tube cryocooler for efficient operation. To obtain the universal 

operating behavior of the inertance phase shifter, a series of 

dimensionless groups are needed, including dimensionless diameter, 

dimensionless length of the inertance tube, and dimensionless 

acoustical power. Two most typical cases of the inertance tube phase 

shifter configurations, infinite reservoir volume and zero reservoir 

volume are highlighted in modeling. Another unique feature of the 

work is that oscillating turbulent flow effect is incorporated to make 

the universal scaling law well describe practical operating behavior of 

the inertance tube shifter. Lots of figures are provided to quickly 

choose an optimal inertance tube phase shifter. 


China(Grant. No.50625620) 

C2-T-03 Impedance Measurements of Inertance Tubes at 

High Frequency and Pressure 

M.A. Lewis, NIST. 

Previous comparisons between measured and calculated inertance 

tube impedance were made at frequencies below 70 Hz and average 

pressures below 3 MPa. In this paper we present results on similar 

comparisons for frequencies up to 120 Hz and average pressures up to 

3.5 MPa. Measurements were made on inertance tubes from 1.0 mm 

to about 3.0 mm, as well as a double inlet arrangement. Pressure 

ratios were varied from 1.1 to 1.4, and acoustic powers up to about 

100 W were used in these measurements. The higher frequencies 

have the potential of reducing the size of both the pressure oscillator 

and the cold finger for a given refrigeration power. The smaller cold 

finger also leads to faster cooldown. In these experiments flow at the 

entrance to the inertance tube was determined from measurements of 

the calibrated pressure drop across a stack of screens. The wide 

range of frequencies and acoustic powers covered in these 

measurements enable us to separate the effects of compliance and 

inertance in the comparisons with transmission line and 

thermoacoustic models. 

Thursday, 07/19/07 Poster 

9:00am - 10:30am 

C3-B High Frequency Pulse Tube Pressure 

Wave Generators 

C3-B-01 Investigation on the dynamic behavior of linear 

compressor in Stirling-type pulse tube refrigerator 

J. Ko, S. Jeong, KAIST. 

This paper describes the experimental study of the dynamic behavior 

of linear compressor in Stirling-type pulse tube refrigerator (PTR). 

The dynamic behavior of the piston is closely coupled with the 

hydraulic force of the gas and, therefore, directly influenced by the 

specific load condition of the pulse tube refrigerator. In the 

experiment, the frequency response of the pressure at each 

component, the cooling performance and the piston displacement are 

measured while the alternative current with the fixed magnitude is 

supplied to the cryocooler. The linear compressor in this study is 

originally designed for the Stirling cryocooler and its maximum input 

power is approximately 200 W. The pulse tube refrigerator is 

configured as in-line type and an inertance tube is incorporated as the 

phase control device in the pulse tube refrigerator near the resonant 

frequency. The pressure difference between both ends of the piston 

imposes the additional stiffness and the PV power at the compression 

space can be considered as the damping effect in the vibration system 

of the piston. From the experimental results, the effect of the gas force 

on the dynamic behavior of the piston is discussed. The dynamic 

relation among the input current, the displacement of the piston, the 

pulsating pressure and the cooling performance is also studied. 

This work was supported by ETEP (Electric Power Industry 

Technology Evaluation and Planning) and KOSEF (Korea Science 

and Engineering Foundation). 



C3-B-02 Development of a Compressor for a Miniature 

Pulse Tube Cryocooler of 2.5 W at 65 K for 

Telecommunication Applications 

N Matsumoto, Y Yasukawa, K Ohshima, T Takeuchi, 

T Matsushita, Y Mizoguchi, Fuji Electric Systems Co., 

Ltd. 

Fuji Electric group has established main technologies for high 

reliability in some stirling cryocoolers for space satellite systems. We 

also have developed and started selling a miniature pulse tube 

cryocooler from 2 W to 3 W at 70 K with 100 W electric power input 

for any commercial applications. In development of a new 

compressor, we introduce a moving magnet to a driving system in 

order to achieve moreover compactness and higher efficiency, not a 

moving coil that is a conventional system with about 70% efficiency. 

And an Expander is adopted a coaxial pulse tube for compactness. 

This development is for cooling a high temperature superconductive 

device in a wireless telecommunication system. The compressor 

requires total compression work of 75 W with 90% efficiency and 

longer than 50,000 hour. 

So far, the primary tests that a part of a moving magnet liner motor 

and a coaxial pulse tube have finished. As next phase, we have made a 

first stage prototype compressor used by the new liner motor, and then 

we have tested the new machine. This paper mainly describes the test 

results of the compressor. 

A Japanese government institution, the Ministry of Public 

Management, Home affairs, Posts and Telecommunications 

C3-B-03 High Frequency Nonmagnetic and Nonmetallic 

Pulse Tube Cryocooler for 80K 

Y.Q. Xun, L.W. Yang, J.H. Cai, J.T. Liang, Y. Zhou, 

Technical Institute of Physics and Chemistry of CAS. 

Many cryogenic apparatus, such as Superconducting Quantum 

Interference Devices (SQUIDs), are quite strict with the cold source 

for their sensitivity to the mechanical and magnetic vibrations. The 

high frequency pulse tube cryocooler (PTC) has considerable system 

advantages due to the reduction of induced electromagnetic 

disturbance and simple mechanism for having no moving part in the 

cold head. By using nonmagnetic and nonmetallic materials for main 

components, we are developing a high Frequency coaxial nonmetallic 

and non-magnetic PTC system with lower vibrations and 

electromagnetic interferences to supply the low-noise cooling for 

highly magnetic flux sensitive high-Tc superconductoring electronics 

including high-Tc SQUIDs. A liner compressor is used to drive this 

version of PTC. With an input electric power of 35W and 42Hz 

operation frequency, this PTC has achieved a no-load temperature of 

76.9K and provides a cooling power of 0.1W at 82K. 

Research supported by National Natural Science Foundation of 

China. (Grant No.50476086) 

C3-B-04 Experimental Investigation on Multi-bypass and 

Fixed Phase-shifter Comparison in Single-stage High 

Frequency Pulse Tube Cryocooler 

X.F. Hou, L.W. Yang, J.T. Liang, Y. Zhou, Technical 

Institute of Physics and Chemistry of CAS. 

A below 40K single-stage high-frequency pulse tube cryocooler(PTC) 

is introduced in this paper. At present, the lowest temperature of 

34.22K with input power of 222W is reached. Four fixed phase shifter 

including inertance tube, inertance tube plus double inlet, inertance 

tube plus multi-bypass and inertance tube plus double inlet plus multibypass 

are compared by experiments. Experiments show that 

inertance tube plus double inlet plus multi-bypass is a best choice to 

apply very low temperature and inertance tube is a good choice to 

apply high temperature and large cooling power in single-stage high 

frequency PTC. And the experiments also show that multi-bypass plus 

nozzle can decrease the DC flow in PTC and increase the performance 

of PTC. 

C3-B-05 Experimental demonstration of a Novel Heat 

Exchange Loop Used for Oscillating Flow Systems 

B. Gao, Technical Inst. of Physics and Chemistry, 

CAS; Graduate University of Chinese Academy of 

Sciences; Z.H. Wu, Technical Institute of Physics and 

Chemistry, CAS; W. Dai, E.C. Luo, Technical Institute 

of Physics and Chemistry,CAS. 

This paper proposed a non-resonant self-circulating heat exchanger 

which uses a pair of single-direction valves to transform oscillating 

flow into steady flow that allows the oscillating flow system’s own 

working gas to go through a physically remote high-temperature or 

cold-temperature heat source. Unlike traditional oscillating flow heat 

exchangers, the length of non-resonant self-circulating heat exchanger 

is not limited by the peak-to-peak displacement. In addition, it is also 

different from the resonant self-circulating heat exchanger that needs 

a specific resonant length [G.Swift and S. Backhaus, A resonant, selfpumped, 

circulating thermoacoustic heat exchanger," Journal of the 

Acoustical Society of America 116, 2923-2938 (2004)]. This 

invention may lead to easy design and fabrication of heat exchangers 

for oscillating-flow refrigeration system with large capacity. To verify 

this idea, we have built an experimental system by incorporating such 

a heat exchanger into a pulse-tube type of Stirling refrigerator. 

Measurements of heat transfer of the heat exchanger under different 

operating conditions including pressure ratio, mean pressure, and 

operating frequency, etc. have been made. Our experiments have 

demonstrated its feasibility and great flexibility for practical 

applications. 

This work was supported by the Natural Sciences Foundation of 

China(Grant. No.50625620). 

C3-B-06 A low cost pressure wave generator using 

diaphragms 

A.J. Caughley, Industrial Research Ltd; D. Haywood, 

Industrial Reserach Ltd; C. Wang, Cryomech. 

The high cost of Pressure Wave Generators (PWGs) is a major barrier 

to the more widespread use of high-efficiency pulse tube and Stirling 

cryocoolers. This paper describes the development and testing of a 

low-cost industrial-style PWG which employs metal diaphragms. The 

use of diaphragms removes the need for rubbing or clearance seals, 

and eliminates contamination problems by hermetically separating the 

gas circuit and the lubricated driving mechanism. The diaphragms 

also allow a conventional low-cost electric motor to be used as the 

power input device for the PWG, via a novel high-efficiency 

kinematic linkage. A first prototype of the diaphragm PWG produced 

approximately 3.3 kW of PV power with a measured electro-acoustic 

efficiency of 69%. Accelerated testing predicts a diaphragm life time 

in excess of 40,000 hours. An additional advantage of the use of 

diaphragms is the ability to directly cool the gas in the compression 

space. This eliminates or significantly reduces the requirement for an 

aftercooler, and further decreases the cost of the whole cryocooler 

system. A pulse tube cryocooler has been successfully run at 

Industrial Research Ltd to 59K with the diaphragm PWG and no 

aftercooler. Another pulse tube cryocooler with the diaphragm PWG 

is undergoing development at Cryomech, the results of which will be 

given in another presentation. 

This programme was supported by the Foundation for Research, 

Science and Techology, New Zealand. 



C3-C Heat Transfer - II 

C3-C-01 Effect of Heated Perimeter on Forced 

Convection Heat Transfer of He I at a Supercritical 

Pressure 

D. Doi, M. Shiotsu, Y. Shirai, Kyoto University; K. 

Hama, Kyoto Unniversity. 

In designing a superconducting coil wound with CICC cooled by 

supercritical helium, accurate knowledge of heat transfer in forced 

flow of He I under supercritical pressure is necessary. However, 

there have been very small number of experimental data and little is 

known on the forced convection heat transfer under supercritical 

pressures. The authors experimentally studied the forced convection 

heat transfer from a flat plate located at a wall of a rectangular duct 

under a supercritical pressure, 2.8 atm and presented the heat transfer 

correlation including a parameter of (L/De) where L is the heater 

length and De is the equivalent diameter. As the perimeter of the duct 

was partially (about 1/4) heated in the experiment, to clarify the effect 

of heated ratio in the perimeter is necessary. In this work, a 

rectangular duct which had the same dimension as used in the 

previous work, 420 mm in length and 5 mm x 6 mm in inner cross 

section, was used. Two pairs of test plates all 5.5 mm in width were 

located face to face on opposite sides of the duct. Each pair having the 

same length of 20 mm and 80 mm, respectively, was connected in 

series electrically. Inlet temperature and flow velocity were varied 

from 2.2 to 6.5 K and 0.1 to 5.2 m/s. Comparison of the obtained 

Nusselt numbers with the former results with a single test pate showed 

clear effect of heated perimeter. Non-dimensional heat transfer 

equation including the effect was presented. 

C3-C-02 Forced convection heat transfer of subcooled 

liquid nitrogen in horizontal tube 

H. Tatsumoto, T. Kato, Japan Atomic Energy Agency; 

Y. Shirai, K. Hata, M. Shiotsu, Kyoto University. 

The knowledge of heat transfer in forced flow cryogenic hydrogen is 

important for the cooling design of hydrogen moderator systems for 

spallation neutron sources. However, there is few experimental data of 

the forced convection heat transfer of cryogenic hydrogen. In order to 

improve prediction of the heat transfer of the hydrogen, experimental 

research of forced convection heat transfer of subcooled nitrogen 

ranging from the pressures of 0.3 to 2.5 MPa was carried out as basic 

research. In this study, an experimental apparatus that could obtain 

forced flow without a pump was developed. The inlet temperatures 

were varied from 77 K to its saturated temperature. The flow 

velocities were varied from 0.1 to 5 m/s. A stainless steel tube with a 

diameter of 5.4 mm and the length of 100 mm was used as a heater. 

The heat transfer coefficients in non-boiling regime and the critical 

heat fluxes of nucleate boiling are higher for higher flow velocity and 

higher subcooling. Obtained Nusselt number (Nu) in non-boiling 

region is proportional to Reynolds number (Re) to the power of 0.7. 

With decreases in Re, Nu approached a constant value that 

corresponds to that in a pool of liquid nitrogen. 

C3-C-03 Heat Transfer Characteristics of Slush Nitrogen 

in Turbulent Pipe Flows 

K. Ohira, J. Ishimoto, Institute of Fluid Science, 

Tohoku University; T. Kura, Tohoku University. 

Slush fluid such as slush hydrogen and slush nitrogen is a two-phase 

(solid-liquid) single-component cryogenic fluid containing solid 

particles in liquid, so that its density and cooling capacity increase 

compared with liquid state fluid. This paper reports the experimental 

results of the forced convection heat transfer characteristics of slush 

nitrogen (63 K) flowing in a 15 mm internal diameter, 625 mm long, 

horizontal, copper pipe. Heat was supplied to the slush nitrogen by the 

heater wound around the pipe wall. The heat transfer coefficient was 

measured with the changes of the velocity and the solid fraction. The 

heat transfer correlation between the Nusselt number and Reynolds 

number was obtained and the differences between two-phase slush 

and one-phase liquid in heat transfer characteristics were clarified. 

C3-C-04 Thermal conductivity measurement of thin film 

(Kapton and PPLP) in low temperature 

S. Yamaguchi, M. Hamabe, H. Takahashi, Chubu 

University. 

One of power applications of high temperature superconductor (HTS) 

is AC power cable, and the design value of the insulation voltage is 30 

to 160 kV in the present time. Thin film is used for electrical 

insulation of the cables, and the thermal resistance of the thin film 

should be low in order to keep low temperature of the HTS tape 

conductor. However, since the measurement of thin film thermal 

conductivity is not easy in low temperature, because the thermal 

resistance of the surface between the different materials must be 

considered, we proposed a new method to measure the thermal 

conductivity of thin film. We measured the thermal conductivity of 

Kapton sheet from the room temperature to 50 K, and get the good 

agreement of the previous data in the room temperature. Therefore, 

this method will be useful to measure the other different thin film 

materials. We also show the thermal conductivity of the PPLP 

(Polypropylene Laminated Paper) from the room temperature to 50 K. 

This work is supported in part by “University-Industry Research 

Project for Private Universities matching fund” by subsidy from 

MEXT, Japan, 2005-2009. 

C3-D Cryofuel Systems 

C3-D-01 A method for low methane sources in MRC 

small scale CBM liquefaction plant 

H. Li, L. Jia, Q. Yin, Q. Fan, G. Yang, X. Liu, W. Bai, 

F. Xu, Z. Ji, J. Cui, Institute of Cryogenics and 

Superconductivity Technology,Harbin Institute of 

Technology. 

Coalbed methane liquefiers in small scale, 5000 to 20000Nm3/d, play 

more and more important roles in Chinese LNG application plan. 

Most CBM sources contain 50% more methane and 50% less air. In 

order to make use of these low methane energy sources, a new fullscale 

separation system was designed and tested using mixed 

refrigerant cycle. A method of air discarding of low CBM sources in 

liquefying process is discussed in this paper. 

C3-D-02 Economic Analysis of Mixed-refrigerant Cycle 

and Nitrogen Expander Cycle in Small Scale Natural Gas 

Liquefier 

Q.S. Yin, H.Y. Li, Q.H. Fan, L.X. Jia, Institute of 

Cryogenics and Superconductivity Technology, 

Harbin Institute of Technology. 

Two types of natural gas liquefaction processes, mixed-refrigerant 

cycle and nitrogen expander cycle were simulated according to the 

applications in small scale LNG plants in China. Their processes 

parameters were optimized and compared. Their economic 

characteristics were analyzed. Although the mixed-refrigerant 

liquefaction process is more complicated than nitrogen expander 

cycle, its energy consumption is only 46% of the nitrogen expander 

cycle. The operation costs of mixed-refrigerant process are lower than 

those of nitrogen expander cycle, so the process is more competitive. 

Referenced the articles published, the energy consumption of the 

optimized mixed-refrigerant cycle reaches the level of propane 

precooled mixed-refrigerant process, which is usually used in the base 

load natural gas liquefaction factory and is the lowest in the mixedrefrigerant 

process. The process is comparatively simple, consumes 

less energy and has economic features. So the mixed-refrigerant 

process is the first choice when one develops small-scale natural gas 

liquefaction device. 



C3-D-03 Scheme Design and Analysis on the Small-scale 

Biogas Liquefaction Cycle 

Q.H. Fan, H.Y. Li, Q.S. Yin, L.X. Jia, Institute of 

Cryogenics and Superconductivity 

TechnologyCHarbin Institute of Technology, 

Harbin. 

The biogas has important practical significance in solving the energy 

crisis as a kind of clean, renewable biological energy of ground. As 

the large-scale concentratedness of the biogas is produced, the 

liquefaction of the biogas is extremely urgent in technical research in 

China. According to the characteristic of the biogas, on the basis of 

mature natural gas purification and liquefaction technology, this paper 

discussed the small-scale biogas liquefaction system of the double 

purposes to purification, liquefaction and recovery of liquefied CO2. 

This paper provides the liquefaction biogas plant process chart, and 

system analysis, and the effects on the key parameters. Finally, the 

thermal parameters of the liquefaction cycle are presented. The result 

provides guidelines for the design of the small-scale biogas 

liquefaction device. 

C3-D-04 Membrane and Joule-Thomson cooler based 

natural gas liquefying system 

A. Piotrowska, M. Chorowski, Wroclaw University of 

Technology. 

The significance of liquid natural gas (LNG) as a fuel in transport and 

power engineering has increased significantly. The composition of 

natural gas is not stable and varies depending on the source. Prior to 

its use the gas should be purified, dehydrated, excess nitrogen should 

be removed and eventually helium recovered. The combination of the 

polymer membrane gas separation technology with Joule –Thomson 

closed cycle can be used as a combined purifying and liquefaction 

system of natural gas. The impurities can be separated on hollow fiber 

membrane and the purified gas can be liquefied with use of Joule- 

Thomson cooler supplied with gas mixture. This system is especially 

suitable for low capacity natural gas sources. A proper choice of gas 

mixture limits temperature difference in the heat exchanger. The paper 

presents thermodynamic analysis and optimization of the system. 

C3-D-05 Development of a magnetic refrigerator for 

hydrogen liquefaction. 

S. Yoshioka, H. Nakagome, Chiba University; K. 

Kamiya, T. Numazawa, National Institute for 

Materials Science; K. Matsumoto, Kanazawa 

University. 

To prepare for the arrival of the hydrogen society, great effort has 

been made on hydrogen liquefaction methods. Compared to 

conventional liquefaction systems using a Joule-Thomson valve, 

magnetic refrigeration for hydrogen liquefaction has great potential 

and its development is an urgent necessity. Magnetic refrigeration 

makes use of magnetocaloric effect, and is well known as an efficent 

method in principal because its cooling cycle can most closely follow 

the Carnot cycle with appropriate heat switches. A liquefaction 

principal of our magnetic refrigerator is based on thermo-siphon 

method, in which liquid hydrogen is condensed directly on the surface 

of magnetic refrigerants and drops downward. This paper reports 

recent progress on development of our magnetic refrigerator and ways 

to make it more efficient by examing design of magnetic refrigerants. 

C3-E Large Scale Systems 

C3-E-01 Performance of liquid xenon calorimeter cryogenic 

system for the MEG experiment 

T. Haruyama, K. Kasami, KEK; H. Nishiguchi, S. Mihara, 

T. Mori, W. Otani, R. Sawada, T. Nishitani, The University 

of Tokyo. 

The rare muon decay physics experiment, so called mu-e-gamma (MEG) 

experiment, is almost ready at the Paul Scherer Institute in Zurich. To meet 

with extremely high sensitivity to catch gamma-ray, 800L of cryogenic 

liquid xenon is used as a main media in the calorimeter. 800 photo 

multipliers (PMT) are all immersed in liquid xenon for capturing scintilaton 

light in liqud. The total dissipation power of these PMTs is expected to be 

about 60 W at 165 K. The scintilation light with a wavelength of 174 nm is 

easily absorbed by residual water in the carolimeter, liquid xenon must be 

purified to the lebel of ppb water contents. This is achieved by using the 

cryogenic centrifugal pump and cold molecular shieves. The total heat load 

of the calorimeter is about 120 W, and the single pulse tube cryocooler 

compensates this heat load. It has a cooling power of 180 W at 165 K, 

developed at KEK and sofisticatedly manufactured at Iwatani Industrial Gas 

corp. The cryogenic system mainly consists of a cryocooler, a liquid pump 

and a 1000L dewar. In addition to the liquid purification, a pump and a 

dewar will be used for an emergency evacuation of large amount of liquid 

xenon. The paper describes successful initial performance test of each 

cryogenic components and total commissioning. 

C3-E-02 Cryogenic Supply for the GERDA Experiment (70m3 

LAr Dewar Tank) 

Ch. Haberstroh, TU Dresden, Lehrstuhl fuer Kaelte- und 

Kryotech. 

In the GERDA experiment (GERmanium Detector Array for the search of 

neutrinoless double beta decay of 76Ge) germanium diodes are suspended in 

a superinsulated copper cryostat filled with liquid argon. The cold medium is 

required since the diodes have to be operated at low temperatures, 

furthermore for shielding against background radiation. In order to achieve 

acceptable radiation levels, a quantity of 70 m³ LAr is needed, placed in a 

surrounding water tank. For the same reason the whole experiment will be 

placed in the underground laboratories in the Gran Sasso mountains, Italy. 

Project leader is the Max-Planck-Institute for Nuclear Physics, Heidelberg. 

In order to avoid any detrimental perturbation inside the dewar vessel, the 

LAr inventory in the main tank should be kept in subcooled state, at a 

working pressure of 1.2 bar absolute at the surface. At the TU Dresden an 

appropriate cryogenic arrangement was designed to match with all these 

requirements. Liquid nitrogen is used as on-hand cooling medium for a zeroboil-off 

system. Special care was taken to cope with the narrow temperature 

span between LAr boiling temperature and triple point. In the proposed 

solution a subcooler located close to the neck provides a stable LAr 

convection inside the main tank. The working pressure is adjusted by a 

controlled, slightly elevated temperature level at the liquid – vapor interface. 

C3-E-03 The results of cooling test on HTS power cable of 

KEPCO 

J.H. Lim, S.H. Sohn, S.D. Hwang, Korea Electric Power 

Research Institute; H.S. Yang, D.L. Kim, Korea Basic 

Science Institute; H.S. Ryoo, Korea Electrotechnology 

Research Institute. 

Due to the inherent characteristics of the superconductivity allowing large 

power transmission capability, many researches on the high temperature 

superconductivity (HTS) power cables have been carried out world widely. 

KEPCO (Korea Electric Power Corporation) had installed three phases, 22.9 

kV, 1250 A, 50 MVA, and 100 m class HTS cable system at Gochang power 

test center of KEPCO. The HTS cable system of KEPCO consists of two 

terminations, HTS power cable, and cooling system. Decompression cooling 

system is chosen for operation characteristics of the HTS cable system 

because it has simple structure and is easier to maintain. Sub-cooled liquid 

nitrogen is used for coolant of the HTS power cable and operation 

temperature of the HTS cable at inlet position is from 66 K to 77 K. 

Circulation cooling tests at different temperatures was performed to 

investigate operating condition and heat loss at loading AC current was 

measured. The results of performance correlated with cooling test will be 

presented in this paper. 

This work was supported in part by the Electric Power Industry Technology 

Evaluation & Planning office, Republic of Korea. 



C3-E-04 Experimental studies on cryogenic system for 

22.9 kV HTS cable system 

S. H. Sohn, J. H. Lim, S. D Hwang, Korea Electric 

Power Research Institute; H. S. Yang, D. L. Kim, 

Korea Basic Science Institute; H. S. Ryoo, Korea 

Electrotechnology Research Institute; C. D. Kim, LS 

Cable Ltd. ; D. H. Kim, S. K. Lee, LS Cable Ltd.. 

In terms of high transmission capacity with lower voltage, a high 

temperature superconducting (HTS) cable system is very attractive 

challenge for power utilities. On the other hand, concomitant 

cryogenic system for the HTS cable system is one of the tantalizing 

problems in the operation. The reliability and maintainability of 

cryogenic system are the key issues to apply it to the real electric 

power grid. Korea Electric Power Corporation (KEPCO) is making an 

attempt to verify the applicability of the HTS cable system to promote 

the efficiency of electric power industry. Since May 2006, 22.9 kV, 

50 MVA, 3-phase, 100 m class HTS cable system with an open 

refrigeration cooling system has been operated at Gochang test yard of 

KEPCO. Concurrently, another HTS cable verification test with the 

same electrical specification and hybrid cooling system has been 

carried out by LS cable Ltd in close proximity with KEPCO’s HTS 

cable system within Gochang test yard. Two GM crycooler, a Stirling 

cryocooler and a pulse tube cryocooler were included in LS HTS 

cable cryogenic system. KEPCO is conducting the operation of the 

open refrigeration system by itself and the evaluation of the hybrid 

system of LS cable with the aspect of facility performance and 

usability. Various tests have been done to confirm the performance of 

HTS cable systems. This paper will compare the cryogenic 

performance of both HTS cable systems and discuss results related 

with cooling tests such as step response. 

This work was supported in part by the Electric Power Industry 

Technology Evaluation & Planning office, Republic of Korea. 

C3-E-05 Design of a Long-Distance Liquid Helium 

Transfer Line 

Ch. Wang, M.C. Lin, L.H. Chang, M.S. Yeh, M.H. 

Tsai, H.H. Tsai, National Synchrotron Radiation 

Research Center. 

Design of a 200-m multi-channel line is to be presented. Currently 

there are two 400-W liquid helium systems in Taiwan Light Source. 

One of them will serve only for SRF application soon, which requests 

only 120-W cooling capacity in normal operation. The spared 

capacity is considered to serve for the SRF test stand in another 

building 200-m away from the cold box and the 2000-L dewar. Thus 

a long transfer line must be constructed to transfer liquid helium from 

the 2000-L dewar to a 500-L dewar in SRF test area. One of the 

major concerns is to reduce the heat loss of this transfer line, while an 

effective cool-down of this transfer line is also considered. The 

challenges come from not only the limited cooling capacity of the 

existing refrigeration system, but also the pressure drop of the long 

distance transfer. A two-phase mathematical model is developed 

initially to estimate the liquid helium transfer feasibility. Major 

design considerations and solutions are presented and discussed 

herein. 

C3-E-06 Thermal stress analysis for a transfer line of 

hydrogen moderator in J-PARC 

H. Tatsumoto, M. Teshigawara, T. Aso, K. Ohtsu, F. 

Maekawa, T. Kato, Japan Atomic Energy Agency. 

The JAEA and KEK proceed with the construction of the Japan 

Proton Accelerator Research Complex (J-PARC). As one of the main 

experimental facilities in J-PARC, a spallation neutron source (JSNS) 

driven by proton beam power of 1 MW is constructed. In JSNS, 

cryogenic hydrogen at supercritical pressure is selected as a 

moderator. Three kinds of moderator, whose vessel is made of 

aluminum alloy, are installed to provide higher neutronic 

performance. The hydrogen transfer line with the length of about 4 m 

is adopted to supply cryogenic hydrogen to the moderator vessel. It 

consists of multiplex pipes such as cryogenic hydrogen supplying 

pipe, vacuum pipe, cryogenic hydrogen return pipe, vacuum pipe, 

helium blanket pipe, and pipe for cooling water. It is necessary to 

minimum the piping size in order to decrease the effect of radiation 

streaming. The piping should have some bend parts to reduce 

radiation streaming and have friction weld joints (aluminum alloy to 

stainless steal). 

Therefore, the piping design should have strict conditions and then we 

considered mechanical stress concentration, deformation, and, 

touching between the pipes due to the thermal shrinkage at the 

cryogenic hydrogen temperature. Then, the thermal stress and the 

thermal shrinkage of the transfer lines were analyzed by using 

computer code such as ABAQUS. The analysis results determined 

support locations to keep the thermal stress below allowable stress and 

also show no interference between each pipes. 

C3-E-07 Cryogenic and vacuum technological aspects of 

the low-energy electrostatic Cryogenic Storage Ring 

D.A. Orlov, M. Lange, H. Fadil, M. Froese, M. 

Grieser, R. von Hahn, V. Mallinger, T. Weber, A. 

Wolf, MPI-K; M. Rappaport, T. Sieber, Weizmann 

Institute of Science. 

A next generation, cryogenic electrostatic ion storage ring will be 

built at the MPI-K in Heidelberg. The machine will store beams with 

kinetic energies between 20 and 300 keV with a main focus on the 

study of molecular ion physics. Wall temperature of about 10 K is 

required to reduce black body radiation in order to obtain and to store 

molecular ions in their rotational ground states. The temperature of 

about 2 K will help to provide extremely low vacuum that will make it 

possible to reach the long beam storage times needed for the 

molecules to complete rotational cooling by the emission of infrared 

radiation. The cryostat was being designed to be bakeable up to 600 K 

to reach 10^{-12} mbar vacuum range at room temperature and to 

obtain extremely low vacuum (less than 1000 molecules per cubic 

centimeter) at a wall temperature of 2 K. 

Despite a strong link of cryogenic and vacuum techniques, in the most 

cases cryogenic materials and instrumentation can not survive a hightemperature 

bakeout which is typically required for UHV systems. To 

test cryogenic and vacuum technological aspects of the CSR we are 

building a prototype. The first results and status of the current work 

with the prototype will be presented. 

C3-F High Temperature Superconducting 

Current Leads 

C3-F-01 Vapor cooled current leads in BEPCII 

Q.J. Xu, Institute of High Energy Physics(IHEP), 

Chinese Academy of Sciences(CAS); C.L. Yi, H.S. 

Chen, H. Yang, J.G. Hu, Z.A. Zhu, W.G. Li, S.P. Li, C. 

Zhang, K. He, R. Ge, M.J. Sang, J. Gao, IHEP,CAS; 

L.Q. Liu, Technical Institute of Physics and 

Chemistry(TIPC),CAS; L. Zhang, TIPC, CAS. 

In the upgrade project of Beijing Electron and Positron 

Collider(BEPCII), Two kinds of superconducting magnets were 

adopted. One is the Beijing Spectrometer III (BESIII) detector 

magnet, the other is the quadrupole(SCQ) magnet. The operating 

currents of them are 3400A, 1100A,600A,130A and 60A respectively. 

Thirteen pairs of Vapor cooled current leads(VCCL) were designed 

and fabricated for these magnets. The paper presents the detail of the 

design, fabrication and the test results of these VCCL. 



C3-F-02 Performance of Heat Exchanger Models in 

Upside-Down Orientation for the Use in HTS Current 

Leads for W7-X 

R. Lietzow, R. Heller , H. Neumann , 

Forschungszentrum Karlsruhe. 

The sc magnet system of the W7-X stellarator requires 7 pairs of 

current leads designed for a maximum current of 18.2 kA. The 

Forschungszentrum Karlsruhe is responsible for the construction, 

manufacturing and performance test of the current leads. Special 

design feature is the installation of the current leads in upside-down 

orientation, i.e., the low temperature end of the current lead is at the 

top and the room temperature end at the bottom side leading to the 

problem of free convection inside the heat exchanger (HEX) due to 

density gradients of the helium between 4.5 K and 300 K (factor 500, 

p = 0.15 MPa). The occurrence of free convection leads to a reduced 

performance of the HEX and results in a higher mass flow rate 

required for the operation of the current leads. To overcome the 

problem it was decided to use HTS material in the temperature range 

between 4.5 K and 60 K. The current lead can then be cooled with 50 

K helium. The main reasons for choosing 50 K are: 50 K helium is 

available at a higher pressure level from the refrigerator and the 

density gradient between 50 K and 300 K is drastically reduced 

(factor 6, p = 0.6 MPa). This will reduce the problem of free 

convection. 

In the paper the performance of HEX mock-ups built of different 

HEX types will be described. The tests were performed with helium 

cooling of various temperatures in normal and upside-down 

orientation. These results were used to select the HEX type for the 

W7-X current leads. 

C3-F-03 Using High Temperature Superconducting 

Leads in a Magnetic Field 


Laboratory; H. Witte, Oxford University. 

HTS leads are increasingly used on superconducting magnets. In most 

cases either the magnet is iron shielded or the magnet is actively 

shielded so that the stray field at HTS leads is low. There are magnets 

where the HTS leads must be located in a magnetic field. The two 

general types of HTS leads that are commercially available are either 

leads fabricated from bulk HTS materials or leads fabricated from 

oriented HTS materials that have one or two planes of favorable 

current density. HTS leads have been fabricated from a variety of 

HTS materials. This paper will discuss how two or three types of 

leads are affected by magnetic field. The performance of a HTS leads 

is determined by the high temperature end of the lead. The protection 

of HTS leads from quenching becomes an important consideration. 

Examples of HTS leads in a magnetic field are shown muon 

ionization experiment (MICE) magnets. 



05CH11231 

C3-F-04 Implementation of HTSC leads for research 

cryostats 

Y. Shiroyanagi, G. Gopalakrishnan, S. An, D. Ko, T. 

J. Gramila, Ohio State University. 

Although the advantage of HTSC wires have been proven both in high 

current applications and in the presence of active cryocoolers, their 

implementation in liquid Helium research cryostats has not been as 

successful. A central difficulty involves the need to establish a 

specific temperature at the warm end of the HTSC wire, which is 

inside the neck of the dewar where temperatures are generally not 

well known. A novel approach to heat sinking of magnet leads[1] has 

enabled detailed numerical modeling of the magnet lead system, 

including the cooling capability of the exiting Helium gas. This 

approach has permitted the incorporation of HTSC leads into He 

research cryostats, while ensuring they remain cold enough to 

superconduct. The overall structure of magnet lead system including 

the HTSC wires, its relevant design features, and our characterization 

of the system will be presented. 

[1] A Novel Approach for Magnet Leads: submitted to JLTP. 

Thursday, 07/19/07 Oral 

10:30am - 11:45am 

C3-G Low Temperature Superconducting 

Magnet Systems - IV 

C3-G-01 CFD Modeling of ITER Cable-in-Conduit 

Superconductors. PART V: Combined Momentum and 

Heat Transfer in a Spiral Rib-Roughened Pipe 

R. Zanino, Politecnico di Torino; S. Giors, Varian 

s.p.a. 

Dual-channel cable-in-conduit conductors (CICC) are used in the 

present design of superconducting magnets for the International 

Thermonuclear Experimental Reactor (ITER). Supercritical helium 

coolant flows both in the annular cable region, and in the central 

channel, delimited by a (perforated) spiral. As the CICC 

axial/transverse size ratio is typically ~ 100, 1D (axial) models are 

customarily used for the CICC, but they require constitutive relations 

for the transverse fluxes. A novel approach, based on Computational 

Fluid Dynamics (CFD), was recently proposed [1], [2] to understand 

the complex transverse thermal-hydraulic processes in an ITER CICC. 

A 3D CFD tool, the commercial FLUENT code, was used to compute 

the friction factor F in spiral rib-roughened pipes, mimicking the 

central channel of an ITER CICC. The results where validated against 

compact heat exchanger and ITER-relevant experiments. That 

analysis is extended here to the problem of combined heat/momentum 

transfer. The model is first validated against 2D and 3D data from 

compact heat exchangers and then applied to the analysis of central 

channel-like geometries relevant for ITER CICC, contributing to a 

better understanding of the role of geometric parameters to optimize 

both F and the Nusselt number (Nu). The question of the applicability 

of the Colburn analogy between F and Nu is also analyzed. 

[1]R. Zanino, et al., Adv. Cryo. Eng. 51 (2006) 1009. 

[2]R. Zanino, et al., Fus. Eng. Des. 81 (2006) 2605. 

C3-G-02 Stability analysis of the ITER TF coil conductor 

L. Savoldi Richard, R. Zanino, Dipartimento di 

Energetica, Politecnico. 

The stability analysis of the International Thermonuclear 

Experimental Reactor (ITER). Toroidal Field (TF) coil Nb3Sn 

conductor is performed using the Mithrandir code [1]. The most 

critical conductor in the winding pack, as well as the most critical 

location along it, is identified by the Vincenta code analysis, which 

also provides the initial and boundary conditions for the stability 

analysis. Two different disturbances are considered: one short in space 

and time (1 cm, 1 ms), simulating a disturbance of mechanical nature, 

the other longer (3 m, 100 ms) corresponding to AC losses (plasma 

disruption). Both disturbances are applied to the superconducting (SC) 

cable at end-of-burn (EOB) in the reference ITER inductive operation 

scenario. Using this approach, the Mithrandir analysis can be 

restricted to the most critical conductor, using a much finer grid than 

Vincenta, in order to capture the details of normal zone initiation and 

possible recovery to SC state. The computed results, in terms of 

minimum quench energy, are compared to the design values. Since the 

results are strongly influenced by the choice of the heat transfer 

coefficient between strands and helium as expected, this effect has 

been also parametrically investigated. 

[1] R.Zanino, S.DePalo and L.Bottura, 



C3-G-03 Design of the KATRIN source cryostat 

S. Grohmann, H. Neumann, Forschungszentrum 

Karlsruhe. 

The KATRIN experiment will measure the mass of electron 

antineutrinos with a sensitivity of 0.2 eV/c^2, based on the precise 

measurement of the tritium beta spectrum. A key component is the 

Windowless Gaseous Tritium Source – WGTS, which will deliver 

10^11 beta decay electrons per second. The WGTS consists in its 

centre of a 10 m long beam tube (BT) that is operated at 30 K, and 

that is surrounded by a series of sc solenoids. Molecular T2 is injected 

in the BT through a central injection chamber and pumped at either 

end. The T2 density profile must have a stability of 0.001 in order to 

limit the systematic errors, yielding stringent requirements on the BT 

temperature homogeneity and stability of ±30 mK and ±30 mK/h, 

respectively. This shall be achieved with a design, where the radiation 

heat load is almost entirely absorbed by LN2 and He coolers on the 

pumping chambers connected to the BT ends. The BT itself will be 

cooled with saturated Ne that is evaporating from a quasi-stationary 

liquid level in evaporator tubes, which are attached to either side of 

the BT and which are part of a thermosiphon. Starting from a 

functional description, we shall explain the cryogenic design of the sc 

magnet cryostat that features 12 fluid circuits with 6 cryogenic fluids. 

Beside the magnet cooling, we shall focus on the layout of the BT 

cooling system, as well as on the preparations for a full-scale 

demonstrator test. 

C3-G-05 Superconductive Undulators, a new source for 

brilliant synchrotron radiation 

R. Rossmanith, S. Casalbuoni, B. Kostka, Research 

Center Karlsruhe, Germany; A. Bernhard, University 

of Karlsruhe, Germany. 

After years of development, superconducting undulators slowly 

become a better alternative to conventional permanent magnet 

undulators. Superconducting undulators have higher fields and are 

more flexible than permanent magnet undulators. The Research 

Center Karlsruhe is a pioneer in this development and built and tested 

the first superconductive undulator in a storage ring (ANKA). The 

tests were so successful that a program to further developments was 

initiated. The results of the tests and the next steps in the development 

are presented in this paper. 

C3-H Non-Aerospace Coolers 

C3-H-01 Dry Dilution Refrigerator with High Cooling 

Capacity 

K. Uhlig, WMI. 

We present the construction concept and cooling capacity 

measurements of a 3,4He dilution refrigerator which was precooled by 

a commercial pulse tube refrigerator. No cryogens are needed for the 

operation of this type of cryostat. The condensation of the helium 

mash was done in an integrated Joule-Thomson circuit which was part 

of the dilution unit. The composition of the dilution unit was standard, 

but its components (still, heat exchangers, mixing chamber) were 

designed for high 3He flow. For thermometry, calibrated RuO chip 

resistance thermometers were available. 

In order to condense the mixture before an experiment, the fridge was 

operated like a Joule-Thomson liquefier with a relatively high inlet 

pressure (4 bar), where the liquid fraction of the circulating 3,4He 

mixture was accumulated in the dilution unit. The condensation took 

about 2 hours, and after 2 more hours of running the temperature of 

the mixing chamber approached its minimum temperature of 10 mK. 

The maximum flow rate of the fridge was 650 µmol/s, and the 

refrigeration capacity of the mixing chamber was 450 µW @ 100mK. 

High cooling capacity, ease of operation and reliability distinguish 

this type of millikelvibn cooler. 

C3-H-02 Research of Application of a New-type of 

Magnetic Refrigerant to Active Magnetic Regenerative 

Refrigeration 

A.T. Saito, S. Kaji, T. Kobayashi, Toshiba 

Corporation; S. Kito, S. Uchimoto, K. Kamiya, H. 

Nakagome, , Chiba University. 

Magnetic refrigeration technique based on the magnetocaloric effect 

(MCE) has received much attention as a potential alternative to 

conventional gas-expansion cooling techniques. The new concept of 

the active magnetic regeneration (AMR) cycle of refrigeration, the 

development of high-performance permanent magnet, and the 

proposal of a new type of high-performance magnetic refrigerants 

have all been accomplished in recent years. These technical 

innovations make it possible to realize magnetic refrigeration over an 

extensive temperature range from cryogenic temperature to room 

temperature using permanent magnets. We succeeded in preparing 

spherical particles of high-performance magnetic refrigerants. This 

paper will present a guide of the application of a new type of highperformance 

magnetic refrigerants which exhibit large MCEs 

especially in low magnetic field to the AMR refrigeration using 

permanent magnets, in terms of MCE, heat regeneration and heat 

exchange between refrigerants and heat transfer fluid. It will be shown 

the physical properties of a new type of magnetic refrigerants, and 

shown a result of simulation of the AMR cycle operation as well as 

experimental results of an AMR cycle operation. 

C3-H-03 Cryogenic Testing of an Active Magnetic 

Regenerative Refrigerator 

A. Rowe, A Tura, B. MacDonald, P. Francescutti, 

University of Victoria. 

Active magnetic regenerative (AMR) refrigeration cycles have been 

proposed as a means of creating compact and efficient devices for 

refrigeration. An interesting application is the development of a 

cooling stage for a hydrogen liquefier operating in the range of 80-20 

K. An AMR test apparatus has been developed for testing magnetic 

regenerators at temperatures ranging from room-temperature to 20 K. 

Near 300 K, no-load temperature spans over 80 K have been produced 

using regenerators composed of two different magnetocaloric 

materials. Modifications to the apparatus have been performed to 

allow testing at cryogenic temperatures. Initial tests near 80 K using 

magnetic fields of 5 T are presented using an AMR composed of 

Gd5Si0.33Ge3.67. In addition, design characteristics of the test 

apparatus, problems encountered, and suggestions for improving 

experimental results are discussed. 

The financial support of Natural Resources Canada, CFI, BCKDF, 

and the Natural Sciences and Engineering Research Council of 

Canada is greatly appreciated. 

C3-H-04 The Use of Small Coolers in a Magnetic Field 


Laboratory; H. Witte, Oxford University. 

Small 4 K coolers are increasingly used to cool superconducting 

magnets. These coolers are usually used with HTS leads. In most 

cases, either the magnet has an iron shield or the magnet is actively 

shielded so that the stray field where the cooler is located is low. 

There are instances when the cooler must be in a magnetic field. 

There are two types of coolers that are commercially available to cool 

superconducting magnets. These coolers are either GM coolers or 

pulse tube coolers. Since these coolers are different, their sensitivity 

to magnetic fields is also different. This paper will discuss how the 

two types of 

coolers are affected by the stray magnetic field. Strategies for using 

coolers on magnets which generate stray magnetic fields are 

discussed. Examples of coolers in a magnetic field are shown in the 

magnets for the muon ionization experiment (MICE). 



05CH11231. 



C3-H-05 Performance of Helium Circulation System 1 

(HCS1) 

T. Takeda, M. Okamoto, K. Atsuda, A. Kobayashi, K. 

Katagiri, Univ. of Tokyo. 

We have developed a system to collect evaporated helium gas, to cool it 

down to liquid and to return it into a FRP dewar for MEG 

(Magnetoencephalography) using two GM cryocoolers without 

delivering any disturbing noises to the MEG. The key idea is to utilize 

relatively high temperature helium gas (about 40K) cooled by the first 

stage of the GM cryocoolers to get rid of invading heat to the dewar, 

but not to use liquid helium directly to keep the dewar cooled down. 

The gas is fed at the neck tube of the dewar. The evaporated helium gas 

in the dewar is collected swiftly while it is in the low temperature 

(about 8K) and is returned to liquid without using much energy. 

A transfer tube that passes the liquid helium, the low temperature 

helium gas (about 8K) and the relatively high temperature helium gas 

has been developed to accomplish the above idea. A refiner to collect 

the contaminating gases such as oxygen and nitrogen effectively by 

freezing the gases is developed. It has an electric heater to remove the 

frozen contamination in the form of gases into the air. A gas flow 

controller is also developed, which automatically control the heater to 

cleanup the contamination. The magnetic, vibrational and acoustic 

noises are attenuated to be low enough for MEG measurements. The 

system can circulate at least 35.5 litters of evaporated liquid helium per 

day and usable at least for one year without any maintenance. 

C3-H-06 Design Parameters for Cryogenic 

Thermosyphons 

H. Timinger, B. David, R. Eckart, J. Overweg, Philips 

Research Europe-Hamburg. 

Cryogenic thermosyphons are the thermal conductors of choice for a 

variety of applications like e.g. conduction-cooled superconducting 

devices. They exhibit a small effective thermal resistance at small 

cross-sections. A careful design, however, is crucial to ensure 

sufficient heat transport for all possible heat loads. The aim of this 

work is to obtain experimental results on the effective thermal 

resistance dependent on the length, the cross-sectional area, and the 

working fluid fill level of a thermosyphon for different heat loads. 

For the experiments, a modular thermosyphon was designed with 4 

different adiabatic tubes of length [cm]/cross-sectional area [sqcm] 

10/0.8, 10/3.14, 30/0.8, and 30/3.14, which can be mounted between 

condenser and evaporator. The thermosyphon was operated with 

different fill-levels of either nitrogen or neon and different heat loads. 

The thermal resistance between condenser and evaporator was 

determined, dependent on the design parameters mentioned above. 

Additionally, the useful temperature range of operation was 

determined for nitrogen and neon. The results of the experiments are 

summarized in diagrams and provide useful reference data for the 

design of cryogenic thermosyphons. 

C3-I Fluid Mechanics - II 

C3-I-01 Surface oscillation of liquid nitrogen induced by 

step reduction of gravity acceleration 

M. Stief, M.E. Dreyer, ZARM – Univ. of Bremen - 

Germany. 

For space application, which involve the handling of cryogenic liquids 

e.g. liquid hydrogen or oxygen, the concern of free surface behavior 

upon change of acceleration level arises. With reduction of gravity 

acceleration hydrostatic loose there dominance and the free surface 

and therefore the motion of liquids is dominated by capillary forces. 

So far the characteristics of the fluid motion subjected to a sudden 

reduction of gravity acceleration has been mostly investigated with 

conventional storable liquids. Because cryogenic liquids have 

different characteristics, these results provide only limited estimations 

for considered space applications. To overcome this knowledge gap 

experiments with liquid nitrogen inside partly filled right circular 

cylinder have been performed at the droptower in Bremen, which 

provides 4.7s of very low gravity acceleration level and a steep 

transition from 1g to 0g. The oscillation of the free surface where 

optically observed by video system during microgravity and processed 

for detection of the motion of the center location of the free surface 

and contact line of the liquid at the cylinder wall. 

The funding of the research project by the German Aerospace Center 

(DLR) under grant numbers 50JR0011 and 50WM0241 is gratefully 

acknowledged. 

C3-I-02 Pressure drop of cable-in-conduit conductors 

with different void fraction 

C. Marinucci, P. Bruzzone, F. Staehli, EPFL, CRPP 

Fusion Technology; L. Bottura, CERN, AT Dept.. 

Pressure drop cable-in-conduit conductors (CICC) was measured at 

CRPP. The conductors are single channel CICC’s with different void 

fraction in the range 38 to 28 %. Several conductor samples are 

investigated and tested in SULTAN by supercritical helium and in a 

room temperature facility by pressurized water. In particular, 

experiments are performed on samples at different degree of 

compaction, measuring the void fraction after each compression step. 

In this way it is possible to assess the friction factor of the cable 

bundle as a function of the void fraction. The reduction of the 

experimental data to obtain the friction factor as a function of 

Reynolds number is performed by (a) established methods using the 

correlation proposed by Katheder and (b) a new porous media analogy 

model. We discuss the results and in particular the comparison of 

these two methods of correlation. 

C3-I-03 Flow of Saturated Liquid Nitrogen through 

Micro-Scale Orifices 

T.A. Jankowski, E.N. Schmierer, F.C. Prenger, S.P. 

Ashworth, Los Alamos National Laboratory. 

The flow of saturated liquid nitrogen through micro-scale orifices has 

been characterized experimentally. Measurements of pressure drop 

and flow rate were made with liquid nitrogen flowing through orifices 

ranging in diameter from 35 micron to 250 micron, with orifice length 

to diameter ratios ranging from 2 to 15. The design of the 

experimental apparatus, the instrumentation used, and the 

experimental uncertainties are presented. Difficulties with clogging 

of the micro-scale orifices and with obtaining repeatable and reliable 

results at cryogenic temperatures are discussed. Finally, experimental 

results are shown to agree with previous investigations of flow 

through micro-scale orifices using room temperature refrigerants. 

C3-I-04 A Rotating Heat Pipe for Cooling of 

Superconducting Machines 

T.A. Jankowski, F.C. Prenger, E.N. Schmierer, Los 

Alamos National Laboratory; A. Razani, The 

University of New Mexico. 

A curved rotating heat pipe for use in superconducting motor and 

generator applications is introduced here. A numerical model of the 

curved rotating heat pipe [1], which has been validated with room 

temperature experiments, is used to predict the performance of 

rotating heat pipes using cryogenic working fluids. Heat pipe model 

results are compared to results for a single-phase gas-cooled 

refrigeration system in typical superconducting generators and motors. 

The nearly isothermal operation of the heat pipe is shown to reduce 

the temperature gradients seen by the superconducting coil compared 

to the forced flow gas system. Furthermore, because of the passive 

nature of the heat pipe operation, the heat pipe concept may be 

advantageous when considering the overall refrigeration system. 

Finally, because of their modular nature, the use of multiple heat pipes 

provides redundancy in the cooling system. 

[1] T. A. Jankowski, “Numerical and Experimental Investigations of a 

Rotating Heat Pipe,” Ph.D. Dissertation, The University of New 

Mexico, 2007. 



C3-K Thermal Insulation Systems - II 

C3-K-01 Vacuum-Insulated, Flexible Cryostats for Long 

HTS Cables: Requirements, Status and Prospects 

M.J. Gouge, J.A. Demko, ORNL; J.F. Maguire, 

AMSC; M.L. Roden, Southwire Company; C.S. Weber, 

SuperPower, Inc.. 

Several high temperature superconducting (HTS) cable demonstration 

projects have begun operation on the electric grid in the last year with 

the liquid nitrogen-cooled cable contained in one or more vacuuminsulated, 

flexible cryostats with lengths up to 600 meters. These grid 

demonstration projects are prototypes of the anticipated commercial 

market which will require superconducting cable lengths in the 

multiple kilometer range with the vacuum-jacketed cryostats in 

underground ducts providing acceptable thermal insulation for 

decades. The current state-of-the art for flexible cryostats (installation 

constraints, heat loads with a good and degraded vacuum, impact of 

cable bends, getter lifetime and reliability) is discussed. Further 

development needed to meet the challenging commercial HTS cable 

application is outlined. 

Research sponsored by the U.S. Department of Energy - Office of 

Electricity Delivery and Energy Reliability, Superconductivity 

Program for Electric Power Systems under contract DE-AC05- 

00OR22725 with Oak Ridge National Laboratory, managed and 

operated by UT-Battelle, LLC. 

C3-K-02 Heat Flow Measurement and Analysis of 

Thermal Vacuum Insulation 

C. Laa, C. Hirschl, J. Stipsitz, Austrian Aerospace 

GmbH. 

A new kind of calorimeter has been developed to obtain specific 

material parameters needed for the analysis of thermal vacuum 

insulation. A detailed description of the measuring device and the 

measurement results will be given in this paper. 

This calorimeter facility allows to measure the heat flow through the 

insulation under vacuum conditions in a wide temperature range from 

liquid nitrogen to ambient. Both boundary temperatures can be chosen 

within this range. The insulation can be characterized at high vacuum 

or under degraded vacuum, the latter using helium or nitrogen gas. 

The mechanisms of heat transfer have been investigated, namely 

infrared radiation between the reflective layers of the insulation and 

conduction through the interleaving spacer material. A mathematical 

description of the heat flow through the insulation has been derived. 

Based on this the heat flow for a typical insulation material has been 

calculated by finite element analysis by use of the software tool 

ANSYS. Such a transient calculation is needed to determine the time 

to reach thermal equilibrium, which is mandatory for a proper 

interpretation and evaluation of the measurement. 

The new insulation measurement results combined with the proposed 

type of analysis can be applied to better understand the thermal 

behavior of any kind of cryogenic system. 

C3-K-03 Robust Multilayer Insulation for Cryogenic 

Systems 

J.E. Fesmire, B.E. Scholtens, NASA KSC; S.D. 

Augustynowicz, Sierra Lobo, Inc.. 

New requirements for thermal insulation include robust multilayer 

insulation (MLI) systems that work for a range of environments from 

high vacuum to no vacuum. Improved MLI systems must be simple 

to install and maintain while meeting the life-cycle cost and thermal 

performance objectives. Performance of MLI systems in actual use 

has been shown to be much worse than the ideal case. Industry 

products using robust MLI can benefit from improved cost-efficiency 

and system safety. Spacecraft that must store cryogens during all 

mission phases, including orbital/lunar service (high vacuum) and 

ground launch operations (no vacuum) are planned. Future cryogenic 

spacecraft for the soft vacuum environment of Mars are also 

envisioned. Novel materials have been developed to operate as 

excellent thermal insulators at vacuum levels that are much less 

stringent than the absolute high vacuum requirement of current MLI 

systems. 

One such robust system, Layered Composite Insulation (LCI), has 

been developed at the Cryogenics Test Laboratory of NASA Kennedy 

Space Center. The experimental testing and development of LCI is 

the focus of this paper. Compared to MLI under cryogenic 

conditions, LCI thermal performance is shown to be six times better at 

soft vacuum and similar at high vacuum. The apparent thermal 

conductivity (k-value) and heat flux data for LCI systems are 

compared with other MLI systems. 

C3-K-04 Synthesis on the multilayer cryogenic vacuum 

insulation modelling and measurements 

M. Chorowski, J. Polinski, Wroclaw University of 

Technology. 

A thermodynamic approach towards insulation systems in cryogenic 

engineering is proposed. A mathematical model of the heat transfer 

through multilayer insulation (MLI) has been developed and 

experimentally verified. The model comprises both physical and 

engineering parameters determining the MLI performance and enables 

a complex optimisation of the insulation system including the choice 

of the insulation location in a vacuum space. The model takes into 

account an interstitial (interlayer) gas pressure and a shield – spacer 

thermal contact resistance variation with the MLI layer density. The 

paper presents the discussion of MLI performance in different 

conditions and provides comparison of computation results with 

experimental reference data. The optimisation of the insulation for 

different boundary conditions is analysed and concluded. 

C3-K-05 Thermal Performance Comparison of Glass 

Microsphere and Perlite Insulation Systems for Liquid 

Hydrogen Storage Tanks 

J.P. Sass, J.E. Fesmire, D.L. Morris, NASA KSC; Z.F. 

Nagy, S.D. Augustynowicz, Sierra Lobo, Inc.; S.J. 

Sojourner, ASRC Aerospace. 

A technology demonstration test project was conducted by the 

Cryogenics Test Laboratory at the Kennedy Space Center (KSC) to 

provide comparative thermal performance data for glass microsphere 

and perlite insulation for liquid hydrogen tank applications. Two 

identical 1/15th scale versions of the 850,000 gallon spherical liquid 

hydrogen tanks at Launch Complex 39 at KSC were custom designed 

and built to serve as test articles for this test project. Evaporative 

(boil-off) calorimeter test protocols, including liquid hydrogen and 

liquid nitrogen, were established to provide tank test conditions 

characteristic of the large storage tanks that support the Space Shuttle 

launch operations. This paper provides comparative thermal 

performance test results for glass microspheres and perlite for a wide 

range of conditions. Limited results for aerogel insulation material 

are also included. Aerogel-based insulation systems are targeted for 

non-evacuated liquid oxygen tank applications due to cost and 

performance parameters. Thermal performance as a function of 

cryogenic commodity (hydrogen and nitrogen), vacuum pressure, 

insulation fill level, tank liquid level, and thermal cycles will be 

presented. 



New Materials and Technologies for Cost-Efficient Storage and 

Transfer of Cryogens. 



C3-K-06 Cost-Efficient Storage of Cryogens 

J.E. Fesmire, J.P. Sass, D.L. Morris, NASA KSC; Z.F. 

Nagy, S.D. Augustynowicz, Sierra Lobo, Inc.; S.J. 

Sojourner, ASRC Aerospace. 

NASA’s critical cryogenic infrastructure that supports launch vehicle 

operations and propulsion testing is reaching an age where major 

refurbishment will soon be required. A key element of this 

infrastructure is the insulation in large double-walled cryogenic 

storage tanks, for which perlite has been the insulation material of 

choice for decades. New materials are now available that can provide 

improved thermal and mechanical performance. An internal research 

and development project investigated the application of new bulk-fill 

insulation materials and associated technology upgrades to advance 

the overall efficiency of cryogenic storage tanks. Technical, safety 

and affordability data were produced to support NASA program 

decisions on the benefits and risks of using the alternative insulation 

materials, including glass microspheres and aerogel beads. Work was 

divided into three areas: material testing (thermal conductivity and 

physical characterization), tank demonstration testing (liquid nitrogen 

and liquid hydrogen), and system studies (thermal modeling, 

economic analysis, and insulation changeout). The research work 

presents a more cost-effective solution for large-scale cryogenic 

storage worldwide, new cryogenic test equipment and methods, and a 

pathway for mass-efficient storage and transfer of cryogens on the 

Moon and Mars. 





C3-L Accelerator Cryogenics 

C3-L-01 Cooldown of the first sector of the Large Hadron 

Collider: comparison between mathematical model and 

measurements 

L. Liu, Chinese Academy of Sciences; G. Riddone, L. 

Tavian, CERN. 

The first LHC sector (3.3-km long) will be cooled down for the first 

time from room temperature to 1.8 K at the beginning of the year 

2007. For this cool-down, the mass-flow distribution of each cell has 

been optimized using a mathematical model developed to establish 

reference set-points. In this paper, the measured evolution of 

temperatures, pressures, mass-flow rates of helium in each cell of the 

machine as well as in the cryogenic distribution line will be presented 

and compared with the simulation results obtained from the previous 

mathematical model. Possible discrepancies between measurements 

and calculation will be also analyzed for improving the mathematical 

model. 

C3-L-02 Commissioning the cryogenic system of the first 

LHC sectors 

F. Millet, S. Claudet, G. Ferlin, P. Gomes, S. Junker, 

G. Riddone, M. Soubiran, L. Tavian, B. Vullierme, U. 

Wagner, CERN; L. Ronayette, L. Serio, CNRS. 

The LHC machine, composed of eight sectors with superconducting 

magnets and cavities requires a complex cryogenic system providing 

high cooling capacities (equivalent to 18 kW at 4.5 K and 2.4 kW at 

1.8 K per sector produced in large cold boxes and distributed via 3.3- 

km cryogenic transfer lines). After individual reception tests of the 

cryogenic subsystems (cryogen storages, refrigerators, cryogenic 

transfer lines and distribution boxes) performed since 2000, the 

commissioning of the cryogenic system of the first LHC sectors is 

under way since November 2006. 

After a brief description of the LHC cryogenic system and its 

specificities, the commissioning will be reported detailing the 

preparation phase (pressure and leak tests, conditioning and flushing), 

the cool-down or warm-up sequences including the handling of 

cryogenic fluids and finally the powering phase of magnets and 

cavities. Preliminary conclusions of the commissioning of the first 

LHC sectors will be drawn with the review of the critical points 

solved or still pending. Finally this paper will report on the first 

operation experience of the LHC cryogenic system in perspective of 

the commissioning of the remaining LHC sectors and the beam 

injection test. 

C3-L-03 Validation and Performance of the LHC 

Cryogenic System Through Commissioning of the First 

Sectors 

L. Serio, CERN. 

The cryogenic system for the Large Hadron Collider accelerator is 

presently in its final phase of commissioning at nominal operating 

conditions. The refrigeration capacity for the LHC is produced using 

eight large cryogenic plants and eight 1.8 K refrigeration units 

installed on five technical sites. Machine cryogenic equipments are 

installed in a 26.7 km circumference ring deep underground tunnel 

and are maintained at their nominal operating conditions via a 

distribution system consisting of transfer lines, cold interconnection 

boxes at each technical site and a cryogenic distribution line. 

The functional analysis of the whole system during all operating 

conditions was established and validated during the first sectors tests 

in order to maximize the system availability and minimize the 

operation cost. The analysis, operating modes, main failure scenarios, 

results and performances of the cryogenic system are presented. 

C3-L-04 Thermal test of the cryogenic distribution line of 

the first complete sector of the Large Hadron Collider 

K. Brodzinski, S. Claudet, J. Fydrych, F. Millet, G. 

Riddone, L. Serio, M. Strychalski, L. Tavian, CERN; 

M. Chorowski, Wroclaw University of Technology. 

The first of the eight sectors of the Large Hadron Collider (LHC) has 

been completely installed in the underground tunnel and connected to 

its cryogenic distribution line (QRL). The QRL will distribute the 

gaseous and supercritical helium along the 3.3-km long sector. In the 

so-called service modules the supercritical helium is sub-cooled and 

then expanded to produce saturated 1.8 K superfluid helium This 

helium is used as cryogenic refrigerant for the accelerator 

superconducting magnets already immersed in a superfluid helium 

bath at 1.9 K. 

One of the next milestones, after the successful thermo-mechanical 

validation of the QRL alone, carried out in 2005, is the hardware 

commissioning of first complete sector of the LHC. One of the main 

issues of this commissioning is the heat inleak measurements to the 

different circuits located in the QRL as well as in the LHC machine. 

The paper describes the applied heat inleak measurement 

methodology, its accuracy and error estimation, as well as presents the 

main results of the measured heat inleaks at the different temperature 

levels. The measured heat inleaks will be also compared to the results 

obtained from the test of the QRL alone. 

C3-M Pulse Tube Theory and Models 

C3-M-01 Performance Limits of 3He in Pulse Tube 

Cryocoolers 

P. Kittel, Consultant. 

The enthalpy, entropy, and exergy flows of the real gas effects of 4He 

in ideal pulse tube cryocoolers have been described previously. 

Huang, et. al, have recently developed a computer program for the 

thermophysical properties of 3He. This paper uses this model to 

describe how the thermodynamic flows are affected by real gas 

phenomena of 3He in ideal pulse tube cryocoolers. 

Frequently such descriptions take an energy-centric view, 

concentrating on the first law of thermodynamics, the conservation of 

energy. This approach can result in a complex description of the 

cooler in terms of energy and enthalpy flows. 

An alternative is to take an entropy-centric approach. Closely related 

to this is the exergy-centric approach. These descriptions concentrate 

on the second law of thermodynamics, the generation of entropy or 

the destruction of exergy. 

Both the energy-centric and exergy/entropy-centric approaches make 

use of both the laws of thermodynamics and both approaches give 

equivalent descriptions of a cryocooler. However, the latter approach 

can be more useful as it can yield a simpler description, one that 

emphasizes loss mechanisms. 

This paper applies the second law approach to pulse tube cryocoolers. 

The non-ideal gas effects of 3He in Pulse Tube cryocoolers are 

discussed and compared to similar effects from 4He. 

This work was funded through University Affiliated Research Center 

(UARC) Subcontract P0228861. The UARC is managed by the 

University of California, Santa Cruz under NASA Ames Research 

Center Contract NAS2-03144. 



C3-M-02 Design for a Miniature Pulse Tube Cryocooler 

Operating at 150Hz 

Z. Gan, NIST; Cryogenics Lab., Zheijiang Univ.; R. 

Radebaugh, M.A. Lewis, P.E. Bradley, NIST; A. 

Veprik, NIST; Ricor, Cryogenic and Vacuum Systems. 

Recent research shows that a pulse tube cryocooler successfully 

operating at 120Hz achieved 50K with high efficiency at 80K. That 

shows cryocoolers can operate at very high frequency and not be 

limited to about 60Hz. There are many benefits of high frequency 

operation, such as fast cooldown, less temperature oscillation at the 

cold head and small size. But, simply increasing the operating 

frequency leads to large losses in the regenerator. Based on the 

numerical calculations with REGEN 3.2 developed by NIST, it shows 

efficient regenerator operation at high frequencies is possible only 

with high charging pressure above 2.5MPa and with very small 

hydraulic diameters and lengths. For commercially available 

compressors, we have designed a pulse tube cryocooler as small as 

possible while maintaining adiabatic conditions in the pulse tube. The 

length¡äinner diameter of pulse tube and regenerator are 

27mm¡ä1.96mm and 27mm¡ä4.39mm respectively. This paper 

presents a design for pulse tube cryocooler operating at 80K with a 

charging pressure of 5MPa at 150 Hz with the pressure ratio at the 

cold end of 1.30. 

C3-M-03 Modeling and Experiments on Fast Cooldown 

of a 120 Hz Pulse Tube Cryocooler 

S. Vanapalli, H.J.M. terBrake, MESA+ Institute of 

Nanotechnology, Univeristy of Twente; M. Lewis, R. 

Radebaugh, NIST, Boulder, CO, 80305; G. Zhihua, 

3Cryogenics Lab, Zheijiang University, Hangzhou & 

NIST, Boulder, CO 80305. 

The high frequency operation of a pulse tube cryocooler leads to 

reduced regenerator volume, which results in a reduced heat capacity 

and a faster cooldown time. A pulse tube cryocooler operating at a 

frequency of 120 Hz and a filling pressure of 3.5 MPa achieved a noload 

temperature of 50 K and a cooldown time of 11 minutes. The 

cooling power at 80 K is about 3.35 W with a cooldown time of about 

5.5 minutes. The back ground losses were about 0.9 W. This very fast 

cooldown is very attractive to many applications. In this study we 

present an analytical model relating various parameters such as 

regenerator volume, frequency of operation, thermal load and 

cooldown time. A comparison is also done between the analytical 

model, REGEN3.2 numerical calculations and experiments. 

STW-Dutch Technology Foundation for the financial support 

C3-M-04 Approximate Design Method for Single Stage 

Pulse Tube Refrigerators 

John Pfotenhauer, University of Wisconsin - 

Madison. 

An approximate method is presented for the design of a single stage, 

Stirling-type pulse tube refrigerator. The design method begins from 

a defined cooling power, operating temperature, average and dynamic 

pressure, and frequency. Using a combination of phasor analysis, 

approximate correlations derived from extensive use of REGEN3.2, a 

few ‘rules of thumb,’ and available models for inertance tubes, a 

process is presented to define appropriate geometries for the 

regenerator, pulse tube and inertance tube components. In addition, 

specifications for the acoustic power and phase between the pressure 

and flow required from the compressor are defined. The process 

enables an appreciation of the primary physical parameters operating 

within the pulse tube refrigerator, but relies on approximate values for 

the combined loss mechanisms. The defined geometries can provide 

both a useful starting point, and a sanity check, for more sophisticated 

design methodologies. A comparison of the model results with the 

performance of existing pulse tube refrigerators is included. 

C3-M-05 Two-dimensional model analysis for the pulse 

tube of rotating pulse tube refrigerator 

J. Choi, S. Jung, KAIST. 

The objective of this paper is to investigate the rotational effect on the 

Stirling type pulse tube refrigerator which is to be used as an on-board 

cooling system for superconducting rotor. The two-dimensional 

analysis model is applied to study thermohydraulic behavior of 

oscillating flow in the rotating pulse tube. 

Two dimensional differential equations for the viscous compressible 

flow in a pulse tube are solved for limited case of very small 

expansion parameter. In the first order analysis, the enthalpy flow 

which is directly related to the refrigeration power is calculated. The 

result of the first order analysis shows that the net enthalpy flow in the 

pulse tube slightly decreases with the rotation. In the second order 

analysis, the steady components of the second order variables are 

calculated on the bases of the first order solutions and the effects of 

the rotation on the enthalpy flow loss due to the mass streaming are 

evaluated. The slow rotation of the pulse tube reduces the secondary 

steady flow, which decreases the streaming-driven enthalpy flow loss. 

As the rotating speed however, surpasses a certain value, the 

secondary steady flow is generated in the opposite direction, which 

results in the increase of the steady enthalpy flow loss again. In this 

paper, we also performed numerical simulation using a finite-volume 

method and compared the numerical results with the approximate 

solution of the differential equations. 

This work was supported by a grant from Center for Applied 

Superconductivity Technology of the 21th Century Frontier R&D 

Program funded by the Ministry of Science and Technology, Republic 

of Korea. 

C3-M-07 Optimal Pulse-Tube Design Using 

Computational Fluid Dynamics 

R.P. Taylor, G.F. Nellis, S.A. Klein, University of 

Wisconsin. 

Over the past few decades, the pulse-tube cryocooler has been 

transformed from a curiosity to one of the most attractive systems for 

providing reliable cryogenic cooling; it is now used in aerospace, 

medical and superconductor applications. This technology 

development has been enabled by advances in the simulation tools 

that are available for regenerator, compressor, and inertance tube 

design. However, a dedicated design tool for the pulse-tube 

component in a pulse-tube cryocooler and the associated flow 

transitions between the pulse tube and the regenerator and the pulse 

tube and the inertance network has yet to be developed. 

This paper describes the development of a two-dimensional, 

axisymmetric CFD model of the pulse-tube and its associated flow 

transitions operating under conditions that are consistent with a pulsetube 

refrigerator. The model is implemented in the commercial CFD 

package FLUENT. The CFD simulations calculate and delineate the 

various loss mechanisms; these are reported as a percentage of the 

acoustic power at the cold end. A gross figure of merit (the pulse tube 

efficiency) is defined as the ratio of the useful cooling provided to the 

available acoustic power. The practical uses (e.g., determining an 

optimal geometric design) and limitations (e.g., the accuracy) of the 

model are discussed and initial optimization results of the CFD 

simulations are presented. 

This work was supported by the Office of Naval Research under 

contract N00014-06-1-0007. 



C3-N Aerospace Cryogen Storage 

C3-N-01 Cryogenic Propellant Storage Analyses and 

Design Tool Evolved from In-Space Cryogenic Propellant 

Depot Project 

D.W. Plachta, NASA GRC; J. Feller, NASA ARC; R. 

Christie, E. Carlberg, ASRC Aerospace. 

Lunar missions under consideration would benefit with incorporation 

of high specific impulse propellants, such as LH2 and LO2, in the 

propulsion systems provided associated cryogenic propellant storage 

boil-off mass were minimized. Concepts to do so were considered 

under the In-Space Cryogenic Propellant Depot Project. Specific to 

that was an investigation of cryocooler integration concepts for 

relatively large depot sized propellant tanks. One concept proved 

most promising—it moves heat efficiently to the cryocooler over long 

distances via a compressed helium loop. The analyses and designs for 

this were incorporated into a Cryogenic Analysis Tool. That design 

approach is explained and shown herein, as are the analytical trends 

that make it so promising. 

C3-N-02 Optimized heat interception for cryogen tank 

support structure 

E.R. Canavan, F.K. Miller, NASA – Goddard Space 

Flight Center. 

We consider means for using the cooling available in boil-off gas to 

intercept heat conducted through the support structure of a cryogen 

tank. A one-dimensional model of the structure coupled to a gas 

stream gives an analytical expression for heat leak in terms of flow 

rate for temperature independent properties and laminar flow. A 

numerical model has been developed for heat transfer on a thin 

cylindrical tube with an attached vent line. The model is used to 

determine the vent path layout that will minimize heat flow into the 

cryogen tank. The results are useful for a number of applications, but 

the one of interest in this study is the minimization of the boil-off in 

large cryopropellant tanks in low Earth and low lunar orbit. 

C3-N-03 The Performance of Gas Filled Multilayer 

Insulation 

G. L. Mills, V. Y. Kotsubo, Ball Aerospace and 

Technologies Corp.. 

The NASA Exploration Program is currently planning to use 

combinations of liquid oxygen, methane and hydrogen for propulsion 

in future spacecraft for the human exploration of the Moon and Mars. 

This will require the efficient long term, on-orbit storage these 

cryogens. Multilayer insulation (MLI) will be critical to achieving the 

required thermal performance since it has much lower heat transfer 

than any other insulation when used in a vacuum. However, the size 

and mass constraints of these propulsion systems will not allow a 

vacuum shell to be used to provide the vacuum during ground hold 

and launch. An effective solution is to purge the MLI during ground 

hold with an inert gas which is then vented during ascent and on-orbit. 

In this paper, we report on experimental tests and modeling that we 

have done on MLI used to insulate a cryogenic tank. These include 

measurements of the heat transfer of gas filled insulation, evacuated 

insulation and during the transition in between. The water vapor 

pressure of the MLI and its effect on the thermal performance was 

also measured. 

C3-N-04 Development of Cryogenic Composite Over- 

Wrapped Pressure Vessels 

T. DeLay, NASA/MSFC; J. Patterson, HyPerComp 

Engineering; J. Schneider, Mississippi State 

University. 

There have been recent changes in the needs of helium pressurant 

tanks and in propellant tanks for new launch vehicles that have the 

requirement to function at cryogenic temperatures. Cryogenic 

propellants are needed for the upper-stage for NASA’s new ARES-1 

vehicle concept, which also has the requirement for 5,000 psi 

pressurant tanks to be located in the liquid hydrogen tank of a 

LOX/LH2 common bulkhead tank. There is a similar need for 

cryogenic propellant tanks for the developing commercial launch 

business and for alternate fuel ventures to transport liquefied natural 

gas and hydrogen. 

In all of these cases it is important to know how the materials perform 

at cryogenic temperatures in order to minimize weight and to ensure 

safety and reliability. A multi-year collaborative effort has made 

considerable progress in this venture. This effort involved the 

simultaneous development of tank designs, test methods and material 

formulations. Many COPV’s have been tested at cryogenic conditions 

and are supported by cryogenic material tests of candidate fiber and 

resin systems formulated specifically for cryogenic applications. This 

comprehensive approach is also being expanded to addressing issues 

with impact damage tolerance and material degradation due to 

environmental factors. 

C3-N-05 Testing the Effects of Helium Pressurant on 

Thermodynamic Vent System Performance with Liquid 

Hydrogen 

R. H. Flachbart, A. Hedayat, S. Nelson, S. P. Tucker, 

NASA - Marshall Space Flight Center; L. J. Hastings, 

Alpha Technology Inc.. 

In support of the development of a micro-gravity pressure control 

capability for liquid hydrogen, testing was conducted at the Marshall 

Space Flight Center using the Multipurpose Hydrogen Test Bed 

(MHTB) to evaluate the effects of helium pressurant on the 

performance of a spray bar thermodynamic vent system (TVS). 

Fourteen days of testing were performed in August – September 2005, 

with an ambient heat leak of about 70-80 watts and tank fill levels of 

90%, 50%, and 25%. The TVS successfully controlled the tank 

pressure within a +/- 3.45 kPa (+/- 0.5 psi) band with various helium 

concentration levels in the ullage. Relative to pressure control with an 

“all hydrogen” ullage, the helium presence resulted in 10 to 30 per 

cent longer pressure reduction durations, depending on the fill level, 

during the mixing/venting phase of the control cycle. Testing was 

also conducted to evaluate thermodynamic venting without the mixer 

operating, first with liquid then with vapor at the recirculation line 

inlet. Although ullage stratification was present, the ullage pressure 

was successfully controlled without the mixer operating. Thus, if 

vapor surrounded the pump inlet in reduced gravity, the ullage 

pressure can still be controlled by venting through the TVS Joule 

Thomson valve and heat exchanger. It was evident that the spray bar 

configuration, which extended almost the entire length of the tank, 

enabled significant thermal energy removal from the ullage even 

without the mixer operating. 

C3-N-06 Analyzing the Use of Gaseous Helium as a 

Pressurant with Cryogenic Propellants with 

Thermodynamic Venting System Modelling and Test 

Data 

A. Hedayat, S.L. Nelson, R.H. Flachbart, D.J. 

Vermilion, S.P. Tucker, NASA-MSFC; L.J. Hastings, 

Alpha Technology, Inc.. 

Cryogenic propellants are candidate propellants for NASA’s Lunar 

and Mars exploration programs. To provide adequate mass flow to the 

system’s engines and/or to prevent feed system cavitation, gaseous 

helium (GHe) is frequently considered as a pressurant. Also during 

low gravity operations, a Thermodynamic Venting System (TVS) 

concept is expected to maintain tank pressure without propellant 

resettling. Therefore, a series of tests were conducted at the Marshall 

Space Flight Center to evaluate the effects of GHe pressurant on 

pressure control performance of a TVS with liquid nitrogen, 

hydrogen, and methane. The TVS utilized in this effort consists of a 

recirculation pump, Joule-Thomson (J-T) expansion valve, and a 

parallel flow concentric tube heat exchanger combined with a 

longitudinal spray bar. Using a small amount of liquid extracted by 

the pump and passing it though the J-T valve, then through the heat 

exchanger, thermal energy is periodically extracted from the bulk 

liquid and ullage thereby enabling pressure control. The test bed set 

up provided thermal conditioning under both vacuum and ambient 

environments. Transient one-dimensional analytical models of the 

TVS are used to predict the ullage and bulk liquid pressures and 

temperatures. Details of predictions and comparisons with test data 

will be presented in the final paper. 



C3-N-07 Screen Channel Liquid Acquisition Device 

Testing using Liquid Methane 

J.M. Jurns, J.D. Gaby, ASRC Aerospace Inc.; S.A. 

Sinacore, J.B. McQuillen, NASA Glenn Research 

Center. 

Liquid acquisition devices (LADs) can be utilized within a propellant 

tank in space to deliver single-phase liquid to the engine in low 

gravity. One type of liquid acquisition device is a screened gallery 

whereby a fine mesh screen acts as a "bubble filter" and prevents the 

gas bubbles from passing through until a crucial pressure differential 

condition across the screen, called the bubble point, is reached. This 

paper presents data for LAD bubble point data in liquid methane 

(LCH4) for stainless steel Dutch Twill Screens with mesh sizes of 

325x2300 and 200x1400. Data is presented for both saturated and 

sub-cooled LCH4, and is compared with predicted values. These tests 

represent the first known non-proprietary effort to collect LAD data in 

LCH4. 

C3-N-08 Numerical Modeling of Propellant Boil-Off in a 

Cryogenic Storage Tank 

A.K. Majumdar, NASA MSFC; T.E. Steadman, J.L. 

Maroney, Sverdrup; J.P. Sass, J.E. Fesmire, NASA 

KSC. 

A numerical model to predict boil-off of stored propellant in large 

spherical cryogenic tanks has been developed. Accurate prediction of 

tank boil-off rates for different thermal insulation systems was the 

goal of this collaboration effort. The Generalized Fluid System 

Simulation Program, integrating flow analysis and conjugate heat 

transfer for solving complex fluid system problems, was used to 

create the model. Calculation of tank boil-off rate requires 

simultaneous simulation of heat transfer processes among liquid 

propellant, vapor ullage space, and tank structure. The reference tank 

for the boil-off model was the 850,000 gallon liquid hydrogen tank at 

Launch Complex 39B (LC-39B) at Kennedy Space Center, which is 

under study for future infrastructure improvements to support the 

Constellation program. The methodology employed in the numerical 

model was validated using a sub-scale model and tank. Experimental 

test data from a 1/15th scale version of the LC-39B tank using both 

liquid hydrogen and liquid nitrogen were used to anchor the analytical 

predictions of the sub-scale model. Favorable correlations between 

sub-scale model and experimental test data have provided confidence 

in full-scale tank boil-off predictions. These methods are now being 

used in the preliminary design for other cases including future launch 

vehicles. 





C3-O Aerospace Mission Concepts 

C3-O-01 ST9 Large Space Telescope: A Proposed Mission 

to Validate the New Paradigm in Low Temperature 

Cooling 

M. DiPirro, D. Muheim, J. Tuttle, K. Walyus, 

NASA/GSFC; P. Cleveland, Energy Solutions 

International; D. Durand, NGST; A. Klavins, D. 

Tennerelli, J. Tolomeo, LMMSC; C. Paine, 

NASA/JPL. 

NASA’s New Millennium Program has sponsored 5 studies for space 

missions to advance space science related technologies. One of these 

studies, the ST9-Large Space Telescope (LST) will demonstrate 

cooling to 4 to 6 K by passive radiation and an active cooler rather 

than the previous method of stored cryogens. Stored cryogen systems 

are not practical for the larger and longer duration missions of the 

future. Passive radiation is accomplished through the use of a 

deployable, multilayer sunshield which has the property of reflecting 

radiation perpendicular to it while emitting radiation parallel to the 

layers. 

Such a shield is already under development for the James Webb Space 

Telescope (JWST). The JWST shield effectively attenuates solar and 

Earth radiation and thermal radiation and conduction from the 

spacecraft by three orders of magnitude, producing an inner layer 

temperature of 90 K. LST will take this technology several steps 

further. By incorporating two stages of active cooling the LST shield 

will attenuate the warm surroundings by 6 orders of magnitude 

producing a shield with an inner layer at 20 K and a cold base plate 

for a future telescope to below 6 K. This talk will summarize the 

material properties tests, thermal and structural analyses, component 

level test beds, plans for ground verification through the use of 

subscale thermal tests, and mission operations planned for ST9 LST. 

C3-O-02 An Analysis of the Cryogenic Environments for 

the Xeus Mission 

J.S. Reed, P. D’Arrigo , M-C. Perkinson , K. Geelen , 

EADS Astrium Ltd.; I. Hepburn , C. Brockley-Blatt , 

Mullard Space Science Laboratory; T. Bradshaw , L. 

Duband , Rutherford Appleton Laboratory. 

The X-ray Evolving Universe Spectroscopy (XEUS), mission is a 

candidate for the ESA Cosmic Vision 2015-2025 plan, following 

XMM-Newton and Chandra. The presently proposed system consists 

of two Mirror and Detector spacecraft, flying 35m apart at L2. The 

Detector Spacecraft model payload consists of a passively cooled 

wide-field camera at 200K, and one of two narrow-field instruments 

at 300mK and 50mK. As the mission lifetime is 5 years, with a 10 

year goal, long-life closed cycle cooling systems will be required. 

Hence, XEUS will be one of the most complex observatories ever 

flown, with state-of-the-art cryogenic systems. Under contract to 

ESA, Astrium has worked with MSSL, RAL, and CEA-SBT, to 

propose a payload design capable of meeting the demanding 

requirements. Our baseline consists of a double stage ADR at 50mK, 

and a helium sorption cooler at 300mK. Each system will be precooled 

by a closed cycle J-T system, similar to Planck, at 2.5K or 4K, 

which itself will be pre-cooled by a two-stage Stirling cycle cooler, at 

15K or 18K. This paper describes the mission, and discusses the 

cryogenic architecture. 

C3-O-03 USAF Cryogenic Thermal Management System 

Needs 

T. Roberts, F. Roush, Air Force Research 

Laboratory. 

The Air Force Research Laboratory (AFRL) Space Vehicles 

Directorate actively pursues cryogenic refrigeration system and 

system integration technology research to support the research needs 

of the Air Force, Missile Defense Agency, and Department of 

Defense. This effort not only takes into consideration the specific 

cryogenic support requirements of payload components such as 

infrared sensors, but also seeks to minimize the system impact on 

payload and spacecraft operations in terms of power and mass budgets 

or jitter producing vibration. These general thermal management 

needs of missions supporting Air Force space operations are discussed 

with respect to the technology portfolio funded by AFRL in order to 

meet these future requirements. Specific strengths and weaknesses of 

the current state of technology are also compared to these needs. 



C3-O-04 Cryogenic System Challenges for Lightweight 

Superconducting Magnet and Power Systems 

C.E. Oberly, G.L. Rhoads, Air Force Research 

Laboratory. 

Significant savings in weight and volume for operational military 

systems can be gained by employing high temperature 

superconducting (HTS) magnets for electrical power equipment 

operating at both very high and power frequency. The demands on a 

cryogenic system are significantly reduced as temperature rises from 

4.2K to 77K, but military operational challenges remain. While the 

weight, volume and electrical power requirements for HTS systems 

can be reduced by orders of magnitude at 77K, the cryogenic system 

remains as a deterrent to quick implementation of HTS technology. 

Military readiness and field operations do not permit optimal, 

continuously cooled, cryogenic systems. Extreme ambient 

temperatures drive commercial refrigerators out of their performance 

envelope. Rapid cooldown requirements in the range of 1 to 4 hours 

are difficult to meet with a lightweight refrigerator coupled to a 

sizeable HTS cold mass. Liquid heat transport systems are penalized 

by makeup gas in remote field operations where many cooldowns 

from ambient are required. Multiple rapid cooldowns creat 

thermomechanical stresses on the new HTS magnet and power 

systems that have not yet been fully explored. Several examples of 

HTS military magnet and power systems are explored and compared 

to provide insight into the need for future cryogenic systems for 

challenging military systems. New refrigeration approaches are 

discussed to meet the future demands of military systems. 

This work has been supported by the Air Force Research Laboratory 

and the Air Force Office of Aerospace Research. 

C3-P Novel Cryostats 

C3-P-01 Subcooled Liquid Oxygen Cryostat for 

Magneto-Archimedes Particle Separation by Density* 

D.K. Hilton, D. Celik, S.W. Van Sciver, NHMFL/FSU. 

An instrument for the separation of particles by density (sorting) is 

being developed that uses the magneto-archimedes effect in liquid 

oxygen. With liquid oxygen strongly paramagnetic, the magnetoarchimedes 

effect is an extension of diamagnetic levitation. The 

instrument will be able to separate ensembles of particles from 100 

µm to 100 nm in size, and vertically map or mechanically deliver the 

separated particles. The instrument requires a column of liquid 

oxygen that is nearly isothermal, free of thermal convection, 

subcooled to prevent nucleate boiling, and supported against the 

strong magnetic field used. Thus, the unique cryostat design that 

meets these requirements is described. It consists in part of a column 

of liquid nitrogen below for cooling the liquid oxygen, with the liquid 

oxygen pressurized with helium gas to prevent nucleate boiling. 

*Research supported by IHRP Grant No. 5057. 

C3-P-02 Novel Integration of a 6T Cryogen-Free 

Magneto-Optical System with a Variable Temperature 

Sample Using a Single Cryocooler 

A.B. Berryhill, D.M. Coffey, Cryomagnetics, Inc.. 

Cryomagnetics` new “C-Mag Optical” Magneto-Optic Property 

Measurement System is a versatile materials and device 

characterization system that allows the researcher to simultaneously 

control the applied magnetic field and temperature of a sample while 

studying its electrical and optic properties. The system integrates a 

totally liquid cryogen-free 6T superconducting split-pair magnet with 

a variable temperature sample space, both cooled using a single 4.2K 

pulse tube refrigerator. To avoid warming the magnet when operating 

a sample at elevated temperatures, a novel heat switch was developed. 

The heat switch allows the sample temperature to be varied from 


C3-Q High Frequency Pulse Tube Coolers 

C3-Q-01 Numerical simulation of a three-stage highfrequency 

Stirling-type pulse tube cryocooler for 4K 

operation 

J.Y. Hu, Graduate University of Chinese Academy of 

Sciences; Z.W. Wu, E.C. Luo, W. Dai, Technical 

Institute of Physics and Chemistry, CAS. 

The thermoacoustically driven two-stage pulse tube cooler recently 

has already reached a lowest temperature of about 18K in our lab. In 

order to further decrease the cooling temperature to 4K, we are 

developing a three-stage Stirling-type pulse tube cooler working at 

about 25Hz. Thermoacoustic theory is a powerful tool for 

understanding the working mechanism of many regenerative 

cryocoolers. Thus, this theory will be employed to simulate the threestage 

pulse tube cryocooler in this paper. As we know, in high 

frequency pulse tube cryocoolers, the main losses come from their 

regenerators. So the structure parameters and thermal properties of the 

regenerators must be carefully designed and considered. Some special 

materials and flow structures for the regenerators with lower 

resistance and high heat capacity were tested in this cooler 

numerically. Besides this, the dimensions of the regenerators and the 

pulse tubes were also optimized to get proper phase relationship 

between the velocity and pressure waves. According to our simulation 

result, when the input pressure ratio is about 1.25, the first and second 

stage cold tips can respectively work at about 65K and 20K, and a 

lowest cooling temperature of the third stage may reach about 4K. 



C3-Q-02 Development and research of pulse tube 

refrigerators at CAS in China 

L. Yang, J. Liang, Z. Yuan, Technical Institute of 

Physical and Chemistry of CAS. 

This paper gives the review of pulse tube research in the past several 

years at Technical Institute of Physical and Chemistry, former 

Cryogenic Lab. 

One main work is to develop high frequency high efficiency PTC to 

satisfy the application at 80K temperature scope. Four different sizes 

coaxial PTCs have been developed: One is miniature version PTC to 

provide cooling of 0.1-1W/80K, in this work, we have the PTC of 

outside diameter of 6mm prototype. Another miniature version PTC is 

to provide 0.3-1.5W/80K cooling power. The small version PTC is to 

provide 0.5W-3W/80K cooling power, while the large version PTC is 

to provide 2W-10W/80K cooling power. These works covers most of 

the requirements at 80K temperature scope in China. 

Another work is to develop high frequency high efficiency PTC to 

satisfy the application at below 50K temperature scope. One is to 

develop single stage PTC that could reach below 30K. Multi-stage 

high frequency pulse tube refrigerator was also our interest for 

potential application and a 16K two-stage PTC is available. 

We are developing non-mental high frequency PTCs also. Our target 

is to acquire low temperature at low input power, for example 

0.1W/80K with 20W input. 

We are also developing single stage low frequency pulse tube for 20- 

40K application. 

Besides the PTCs aims for practical application, we are also do 

research on numerical simulation and oscillating flow research 

experiment. This will also be reported. 

This work is supported by Natural Sciences Foundation of China 

(50206025, 50476086 ). 

C3-Q-03 High Frequency Miniature Reservoir-less Pulse 

Tube Cryocooler 

I Garaway, G Grossman, Technion - Israel Institute of 

Technology. 

A miniature high frequency reservoir-less pulse tube cryocooler has 

been designed and tested in our laboratory. The cryocooler having a 

regenerator length of 12.0 mm and an overall volume of 2.3cc 

(excluding the compressor) reached a low temperature of 151K. This 

study shows that it is possible to miniaturize a pulse tube cryocooler 

to very short regenerator length by implementing a few basic 

principles: Most importantly, higher operating frequencies at small 

tidal displacements with increased helium fill pressures. This study 

also shows that as the operating frequency of a miniature cryocooler 

increases, the reservoir becomes less necessary as a phase shifting 

device. At higher frequencies and smaller inertance tube geometries 

the impedance and capacitance of the inertance tube itself takes over 

the phase shifting task. This study shows that in a high frequency 

(greater than 250Hz) system the volume of such an inertance tube can 

be decreased to values of less than 1cc. An outline of the design and 

modeling principles will be presented along with some details of the 

experimental apparatus and testing procedures. 

C3-Q-04 Development of a low cost high frequency pulse 

tube cryocooler 

C. Wang, Cryomech, Inc.; A. Caughley, D. Haywood, 

Industrial Research Ltd. 

In cooperation with Industrial Research Ltd (IRL), Cryomech, Inc. is 

developing a low cost high frequency pulse tube cryocooler. The 

valveless compressor, developed by IRL, employs two S.S. 

diaphragms and novel kinematics driven mechanism. The pulse tube 

cold head has co-axial configuration and is separated from the 

compressor by 1.5m. The diaphragm compressor and co-axial pulse 

tube cold head ensure low cost on the manufacturing. The design is 

also user friendly for integration. The preliminary tests demonstrate 

encouraging results of the system. It has a bottom temperature of 40 

K and over 100W at 80K for 3.6kW power input. The design goal is 

to have a cooling capacity of 200W at 80K. The improvement of the 

pulse tube cryocooler is undergoing. The details of the design, 

development and performance will be presented in the conference. 

Friday, 07/20/07 Plenary 

8:00am - 9:00am 

C4-A Friday Plenary Session 

C4-A-01 Overview of the Liquefied Natural Gas (LNG) 

Industry 

R.T. Rogers, AGL Resources. 

The presentation will include an overview of the different types of 

LNG Plants, from the small Satellite LNG Plants to the large Import 

or Base Load LNG Terminals. The talk will also present information 

about AGL Resources` LNG Operations, as AGL Resources is the 

largest LNG Peak Shaving Operator in the Southeast United States. 

The presentation will also include a demonstration of the 

characteristics of LNG as well as address the phenomenon of LNG 

Tank Rollover. 



Friday, 07/20/07 Oral 9:15am - 

10:45am 

C4-B Superconducting RF Cavities and 

Cryosystems - II 

C4-B-01 ILC Cryogenic Systems Reference Design 

T. Peterson, M. Geynisman, A. Klebaner, J. 

Theilacker, Fermilab; V. Parma, L. Tavian, CERN. 

A Global Design Effort began in 2005 to study a TeV scale electronpositron 

linear accelerator based on superconducting radio-frequency 

(RF) technology, called the International Linear Collider (ILC). In 

early 2007, the design effort culminated in a reference design for the 

ILC, closely based on the earlier TESLA design. The ILC will consist 

of two 250 GeV linacs, which provide positron-electron collisions for 

high energy physics research. The particle beams will be accelerated 

to their final energy in superconducting niobium RF cavities operating 

at 2 Kelvin. At a length of about 12 km each, the main linacs will be 

the largest cryogenic systems in the ILC. Positron and electron 

sources, damping rings, and beam delivery systems will also have a 

large number and variety of other superconducting RF cavities and 

magnets, which require cooling at liquid helium temperatures. Ten 

large cryogenic plants with 2 Kelvin refrigeration are envisioned to 

cool the main linac and the electron and positron sources. Three 

smaller cryogenic plants will cool the damping rings and beam 

delivery system components predominately at 4.5 K. This paper 

describes the cryogenic systems concepts for the ILC. 

C4-B-02 Installation and Commissioning of the 

Superconducting RF Linac Cryomodules for the ERLP 

A.R. Goulden, R. Bate, CCLRC Daresbury 

Laboratory UK; R.K. Buckley, S.M. Pattalwar, 

CCLRC Daresbury Labpratory UK. 

An Energy Recovery Linac Prototype (ERLP) is currently being 

constructed at Daresbury Laboratory (UK), to promote the necessary 

skills in science & technology, particularly in photocathode electron 

gun and Super Conducting RF, to enable the construction of a fourth 

generation light source, based on energy recovery linacs-4GLS [1]. 

The ERLP uses two identical cryomodules, one as a booster cavity 

accelerating the beam to 8.5 MeV, the other as a linac module in the 

re-circulating loop with an energy gain of 24.5 MeV. Each module 

consists of two nine cell cavities operating at a frequency of 1.3GHz 

and a temperature of 2K. As there is no energy recovery in the booster 

it requires a peak power of 53kW; whereas the linac module only 

requires 8kW. The RF power is supplied by 4 IOTs. The maximum 

heat load or the cooling power required in the Super Conducting RF 

system is 180W at 2K and is achieved in two stages: a LN2 precooled 

Linde TCF050 liquefier produces liquid helium at 4.5K, 

followed by a 2K cold box consisting of a JT valve, recuperator and 

an external room temperature vacuum pumping system. 

This presentation reports the experience gained during, installation, 

commissioning and the initial operation of the cryomodules. 

C4-B-03 Initial Operating Experience for the ISAC-II 

SC-Linac at TRIUMF 

I. Sekachev, W. Andersson, R. Laxdal, G. Stanford, 

TRIUMF. 

A first stage of the heavy ion superconducting linac cryogenic system 

comprising a 500W LHe refrigerator and distribution system has been 

installed and started operation at TRIUMF. The early experience with 

the cryogenic systems including data of the thermal loads and 

refrigerator performance will be presented. 

C4-B-04 Operation of the Superconducting Linac at the 

Spallation Neutron Source.* 

I. E. Campisi, F. Casagrande, M. Crofford, M. 

Howell, Y. Kang, S. H. Kim, Z. Kursun, P. Ladd, D. 

Stout, W. Strong, ORNL/SNS; M.S. Champion, FNAL. 

At the Spallation Neutron Source, the first fully operational pulsed 

superconducting linac has been active for about two years. During this 

period, stable beam operation at 4.4 K has been achieved with beam 

for repetition rates up to 15 Hz. Lower temperatures have been 

occasionally attained to study conditions required to support full beam 

power delivery, which requires 60 Hz RF and beam pulses of 1 

millisecond. A large amount of data has been collected on the pulsed 

behavior of cavities and cryomodules at various repetition rates and at 

various temperatures. This experience will be of great value in 

determining future optimizations of SNS as well in guiding in the 

design and operation of future pulsed superconducting linacs. 

This paper describes the details of the cryogenic system and RF 

properties of the SNS superconducting linac. 

*SNS is managed by UT-Battelle, LLC, under contract DE-AC05- 

00OR22725 for the U.S. Department of Energy 

C4-B-05 Cryogenic Infrastructure for Fermilab’s ILC 

Vertical Cavity Test Facility 

R. Carcagno, C. Ginsburg, Y. Huang, B. Norris, J. 

Ozelis, T. Peterson, R. Rabehl, C. Sylvester, M. Wong, 

Fermi National Accelerator Laboratory. 

Fermilab is building a Vertical Cavity Test Facility (VCTF) to provide 

for R&D and pre-production testing of bare 9-cell, 1.3 GHz 

superconducting RF (SRF) cavities for the International Linear 

Collider (ILC) program. This facility is located in the existing 

Industrial Building 1 (IB1) where the Magnet Test Facility (MTF) 

also resides. Helium and nitrogen cryogenics are shared between the 

VCTF and MTF including the existing 1500W @ 4.5K helium 

refrigerator with vacuum pumping for super-fluid operation (125 W 

capacity at 2K). 

The VCTF is being constructed in multiple phases. The first phase is 

scheduled for completion in mid 2007, and includes modifications to 

the IB1 cryogenic infrastructure to allow helium cooling to be directed 

to either the VCTF or MTF as scheduling demands require. At this 

stage, the VCTF consists of one Vertical Test Stand (VTS) cryostat 

for the testing of one cavity in a 2 K helium bath. 

Planning is underway to provide a total of three Vertical Test Stands 

at VCTF, each capable of accommodating two cavities. Cryogenic 

infrastructure improvements necessary to support these additional 

VCTF test stands include a dedicated ambient temperature vacuum 

pump, a new helium purification skid, and the addition of helium gas 

storage. 

This paper describes the system design and initial cryogenic operation 

results for the first VCTF phase, and outlines future cryogenic 

infrastructure upgrade plans for expanding to three Vertical Test 

Stands. 

C4-B-06 European XFEL-Linac Two-Phase Helium II 

Flow Simulations 

V. Gubarev, B. Petersen, D. Sellmann, DESY; Y. 

Xiang, GSI. 

The superconducting 1.3-GHz niobium cavities of the XFEL linear 

accelerator will be cooled in a bath of liquid helium II at a 

temperature of 2K. The liquid helium II supply of the 1.7-km long 

linac is subdivided in sections of 150m length. In these sections a two 

phase flow of helium II liquid and corresponding vapor occurs. A 

stable stratified smooth helium flow has to be maintained for the RF 

operation of the cavities, to avoid any microphonic effects. A 

computer code has been developed to simulate the two phase flow in 

the XFEL-linac. The flow characteristics at different cryogenic loads 

and tube dimensions have been calculated. The results are shown and 

the consequences for the design of the XFEL-cryomodules are 

discussed. 



C4-C Aerospace Components 

C4-C-01 Developments on Vibration Free Sorption 

Cooling 

J.F. Burger, R.J. Meijer, H.J. Holland, H.J.M. ter 

Brake, University of Twente; A. Sirbi, ESA-ESTEC. 

At the University of Twente, a breadboard 4.5 K sorption cooler was 

developed under an ESA-TRP contract. It has no moving parts and, 

therefore, is essentially vibration-free. Moreover, it has the potential 

of a very long life. This cooler is a favorite option for missions such 

as ESA’s Darwin mission, which is a future space interferometer 

consisting of a few free flying telescopes and a central beam 

combiner. Because of the optics involved, hardly any vibration can be 

tolerated. 

The cooler consists of a hydrogen stage cooling from 80K to 14.5K 

and a helium stage establishing 10mW at 4.5K. Both stages use 

micro-porous activated carbon as the adsorption material. The two 

cooler stages need 8W of input power and are heat sunk at two 

passive radiators at temperatures of about 50 and 80K. We developed 

and built a demonstrator of the helium stage. In the paper, the design, 

realization and tests of this demonstrator cooler will be reviewed. 

Following this review, we will describe further developments on 

improved carbon cells and sub-components such as passive check 

valves. Furthermore, trends will be presented that consider the use of 

other working fluids at different temperature ranges. 

C4-C-03 Cryogenic Quad-redundant Thermal Switch 

B. C. Thompson, B. Lloyd, Space Dynamics 

Laboratory; S. H. Schick, Practical Technology 

Solutions Inc.; L. Li, Utah State University. 

A Quad-Redundant Thermal Switch (QRTS) for the James Webb 

Space Telescope has been successfully designed, fabricated, and 

tested at the Space Dynamics Laboratory (SDL). A flight-like 

prototype successfully passed thermal and structural qualification tests 

in a representative space environment and achieved Technology 

Readiness Level 6. The QRTS serves as a high thermal conductance, 

high reliability thermal connect / disconnect between heat sources and 

sinks. The switch consists of an all metallic core switch construction 

packaged in a cross-strapped quad-redundant configuration. 

Actuation of the switch is based on differential thermal expansion. 

The four individual switches are passively closed over the entire 

operational range and actuated open by applying heat to the actuation 

rods. Key qualification tests included: robust characterization of 

thermal closed and open performance from 32 to 313K; and a full 

suite of vibration testing (sine, random, and sine burst). This paper 

presents an overview of the QRTS functionality, thermal and 

structural qualification tests, and resulting switch performance. 

Thanks to D. S. Hansen and K. N. Johnson from Space Dynamics 

Laboratory and S. Glazer from GSFC. Funding for this project was 

provided by GSFC. 

C4-C-04 High Specific Power Motors in LN2 and LH2 

G.V. Brown, J.J. Trudell, NASA Glenn Research 

Center; R.H. Jansen, University of Toledo. 

Low winding resistance and high thermal conductivity in LN2 and 

LH2 allow electric machine windings to be cooled only at end turns to 

preserve slot space for conductor and insulation. End turn layers, 

shaped into heat exchangers, provide large heat transfer area and flow 

channels for nucleate boiling and excellent cooling. Joule heat is 

rejected outside the magnetically active region with low temperature 

rise. The result is very high specific power. “Self-finned” coils in 

LN2 show rms current density 10 times that typical at room 

temperature. A 12/8 switched-reluctance motor of 18 lb 

electromagnetic (EM) weight, with such coils, produced 7.9 kW/lb- 

EM in one second tests at 20 krpm, at an rms current sustainable at 

steady state in uninstalled coils. If the motor can be supplied with 

LN2 and cleared of GN2 bubbles at steady state, the specific power 

will exceed that of any other motor or generator, including 

superconducting machines. On future LH2-fueled aircraft this type 

motor would use fuel for cooling before the fuel is burned. Endcooled 

coils would perform even better in LH2 than in LN2 because 

of further increases in electrical and thermal conductivity. Coils could 

be longer, carry more current without thermal runaway and make less 

boil-off gas. Measurements, analysis and motor performance will be 

presented. 

C4-D Stirling and Pulse Tube Performance 

Enhancement and Modeling 

C4-D-01 A new Mini Pulse Tube Cryocooler with a heat 

interceptor 

Ph. Gully, I. Charles, CEA-Grenoble/SBT; R. Briet, 

CNES-Toulouse. 

An experimental study of a coaxial mini Pulse Tube Cryocooler is 

presented. First various rejection temperatures for the pulse tube warm 

end and the compressor foot have been investigated. It is shown that 

the rejection temperature at the warm side of the Pulse Tube is a key 

parameter and that the heat sink of the cooler can be located only at 

this point. Heat repartition between the pulse tube and the compressor 

as a function of the rejection temperatures is discussed. 

The coaxial mini pulse tube cooler has been equipped with a heat 

interceptor in order to take advantage of passive intermediate free 

cooling available for some space missions. The heat interceptor is a 

simple copper collar mounted on the half warm side of the regenerator 

tube. It is shown that this concept allows boosting the cryocooler 

performances with a small associated passive radiator thermally 

linked to the interceptor. As an example, a 0.05m2 radiator allows to 

increase the cooling power at 80K from 1.5 to 2 W. Performances 

obtained for different heat interceptor positions are presented and 

discussed. 

Thanks to SBT experimental team for its help and CNES for its 

financial support 

C4-D-02 A thermoacoustically-driven micro-miniature 

pulse tube cooler operating with high frequency of 300 to 

500Hz 

G.Y. Yu, S.L. Zhu, Graduate University of Chinese 

Academy of Sciences; E.C. Luo, Technical Institute of 

Physics and Chemistry, CAS; W. Dai, Technical 

Institute of Physics and Chemistry,CAS. 

High frequency thermoacoustic cryocooler system is quite attractive 

to small-capacity cryogenic applications such as for aerospace 

cooling. Recently, a no-load temperature of 95K and 79.6K have been 

obtained on a 300Hz pulse tube cooler driven by a standing-wave 

thermoacoustic engine with 750W and 1750W heating powers in our 

lab, respectively. However, the standing-wave thermoacoustic engine 

is intrinsically irreversible, which limits the global thermal efficiency 

of the system. Aimed for a cooling power of about half Watts at 80K 

with a higher thermal efficiency, a high frequency thermoacoustic- 

Stirling heat engine was designed to drive a pulse tube cooler in the 

work to be presented here. Ideas such as tapered resonator, acoustic 

amplifier tube and half wavelength inertance tube phase shifter 

(without reservoir) are used to effectively suppress the harmonic 

modes, amplify the acoustic pressure wave available to the pulse tube 

cooler and provide desired acoustic impedance for the pulse tube 

cooler, respectively. Influence of average pressure, heating power, 

mesh size and coupling mechanism are given in detail. Up to now, a 

lowest temperature of 129K has been obtained on the system with 

3.93MPa helium gas, 309Hz working frequency and 400W heat input. 

Numerical simulations based on the linear thermoacoustic theory have 

also been done for comparison with experimental results, which 

shows reasonable agreement. Further optimization work is being 

under way. 



C4-D-03 An Innovative Inertance Device for Pulse Tube 

Cryocoolers 

Sidney Yuan, David Curran, Aerospace Corp. 

The theory behind a Pulse Tube Cryocooler is very similar to that of a 

Stirling cooler with the motion of the displacer replaced by that of the 

gas piston. Some of the best performance of the Pulse Tube coolers 

matches that of the Stirling refrigerator. Obviously, the importance of 

the phase shift mechanism in a Pulse Tube cannot be overemphasized. 

In this paper, an innovative inertance phase-shift device is described. 

The performance of this invention has been validated by analysis 

using the SAGE software. This invention offer tremendous benefit 

over the traditional phase shift devices used in Pulse Tubes. 



C4-D-04 Multistage Pulse Tube Refrigeration 

Performance Mapping of the Lockheed Martin RAMOS 

Engineering Model Cryocooler 

W.D. Scheirer, T.P. Roberts, Air Force Research 

Laboratory. 

The performance mapping of a multistage pulse tube refrigeration 

system has been performed on the Lockheed Martin Russian- 

American Observational Satellite (RAMOS) engineering model 

cryocooler by the Air Force Research Laboratory. The cryocooler 

consists of a two-stage pulse tube coldhead driven by a linear flexurebearing 

compressor. The coldhead and compressor are separated by a 

transfer line of up to one meter. The RAMOS cryocooler is designed 

to deliver 0.75 W of cooling at 75K and 6 W of cooling at 130K. 

Characterization test results include performance mapping at rejection 

temperatures from 275K to 325K, drive frequency variation effects 

from 39 Hz – 65 Hz, as well as results for both steady state and 

transient performance envelopes. The effects of varying operational 

conditions on the transfer line’s non-isothermal behavior will also be 

presented. 

C4-D-05 Design and Performance Optimisation of a 

Coaxial Pulse Tube Cooler 

W. van de Groep, J. Mullie, T. Benschop, F. van 

Wordragen, THALES Cryogenics B.V.. 

Since 2005 Thales Cryogenics has been producing coaxial pulse tube 

coolers under CEA license for applications that are very sensitive for 

mechanical vibrations and require a long lifetime. 

In order to optimise the existing baseline design of the coaxial pulse 

tube Thales Cryogenics has been working on several of the critical 

elements inside the pulse tube. This optimisation should lead to a 

wider application of these pulse tube coolers into high-end civil 

applications. 

This paper describes the work carried out on the optimisation of the 

heat exchangers at the cold tip, the warm-end and the buffer including 

irreversible heat losses caused by disruptions of the gas flow. 

Moreover, the heat exchange of warm end gas to the surroundings has 

been investigated. Also, the impact on cool downtime and the 

sensitivity to internal contamination has been tested. 

Results will enable a design optimisation of the whole range of 

coaxial pulse tube coolers, varying from 1 and 4W at 80K to pulse 

tube coolers of more than 12W cooling power at 80K. 

In this paper, test result, trade-off’s and benefits of the new design 

will be discussed and evaluated. 

C4-D-06 Fast Response Temperature Measurements in 

Stirling Cycle Cryocooler Components 

K, Kar, University of Auckland; M.W. Dadd, P. 

Bailey, C.R. Stone, University of Oxford. 

One reason that heat transfer processes are not well understood is the 

difficulty of obtaining reliable temperature measurements when gas 

temperatures vary rapidly. In the work described here gas 

temperatures have been measured using a fine wire resistance 

thermometer with a 3.8 micron active sensor. The equipment 

represented the basic elements of a cryocooler: a clearance seal linear 

compressor and a wire mesh regenerator. Both were operated close to 

ambient temperature, with gas temperatures being measured close to 

the regenerator. 

The test rig was run at different volume ratios, frequencies (8–50 Hz), 

gases and filling pressures (1–26 bar). The waveforms of the gas 

temperature were found to vary dramatically for differing flow 

regimes. 

The results suggested that the thermometer was measuring the 

temperatures of two distinct volumes of gas, and that the gas must 

remain stratified in the compression space. A flow transition was 

identified from the cycle-by-cycle variations in temperature. The 

critical Reynolds number was determined to be 9.6–11. At the critical 

condition, the temperature was so unstable that fluctuations up to 250 

Hz were observed. A series of validation tests have confirmed that the 

observed temperatures were not artifacts. 

This work was sponsored by the Air Force Office of Scientific 

Research, Air Force Material Command, USAF, under grant number 

FA8655-06-1-3071. 

The U.S. Government is authorized to reproduce and distribute 

reprints for Government purpose notwithstanding any copyright 

notation thereon. 

C4-D-07 Optimal Control Strategies for a Rectified 

Continuous 

Flow Loop Interfaced with a Distributed Load 

H.M. Skye, G.F. Nellis, S.A. Klein, University of 

Wisconsin - Madison. 

Distributed loads are frequently encountered in large deployable 

structures used in space applications such as optical mirrors and focal 

plane electronics. An innovative mechanism for providing distributed 

cooling is an oscillatory pulse-tube cryocooler that is integrated with a 

fluid rectification system consisting of check-valves and buffer 

volumes in order to extract a small amount of continuous flow. This 

continuous flow allows relatively large loads to be accepted over a 

long distance. An additional advantage of the rectified system is that 

ability to provide rapid and precise temperature control via 

modulation of the flow rate in the flow loop. This paper investigates 

this latter capability of the rectifying interface, the ability to control 

the temperature of a distributed load under the influence of various 

thermal disturbances. Temperature regulation is enabled using a 

temperature feedback control of a throttle valve placed in the loop. 

The control parameters are selected to meet temperature regulation 

specifications, including maximum temperature deviation and settling 

time in response to a step change in distributed load. The predicted 

and measured controlled transient behaviors are compared in order to 

demonstrate the temperature control capability. 

This work was supported by the Missile Defense Agency through the 

Air Force Research Laboratory, and by the National Space Grant 

College and Fellowship Program and the Wisconsin Space Grant 

Consortium. The technical assistance of Atlas Scientific is gratefully 

acknowledged. 

C4-D-08 Performance Prediction of PTR for Different 

Pressure Waveforms 

S. Desai, C.K. Pithawala College of Engineering, 

Surat, Gujarat, India; K.P. Desai, H.B. Naik, S.V. 

National Institute of Technology, Surat, Gujarat, 

India; M.D. Atrey, Indian Institute of Technology 

Bombay, Mumbai, India. 

Many researchers have shown that the performance of the PTR 

depends significantly on the pressure waveforms generated by the 

rotary valve in a G-M type PTR. Some literature has shown this effect 

experimentally for various waveforms. The design of the rotary valve 

therefore is very critical in order to generate an optimum pressure 

waveform. However, if the optimum waveform for obtaining 

maximum cooling power is known, it will help the valve design 

significantly. In view of this, the valve design would be improved 

significantly if the performance of the PTR could be predicted with 

reasonable accuracy for any pressure waveform. The present paper 

aims at developing a procedure to generate such predictions of the 

PTR performance for different pressure waveforms. This will help to 

determine an optimum pressure waveform for a given PTR 

configuration and will be useful in a significant way for the design of 

the rotary valve. 

An isothermal model of the PTR has been developed for various 

operational modes viz, Basic, OPTR, DIPTR, and has been validated 

with experimental results. The model is then extended to predict the 

PTR performance for various pressure waveforms. The experimental 

data, available in literature in the form of different pressure waves for 

a given PTR configuration, has then been analyzed. A comparison 

between the experimental results and the model predictions has been 

presented. 



C4-E Cryosystems for Fusion 

C4-E-01 Cryogenics for Fusion 

P. Dauguet, G.M. Gistau-Baguer, M. Bonneton, J.C. 

Boissin, E. Fauve, J.M. Bernhardt, J. Beauvisage, F. 

Andrieu, Air Liquide. 

Fusion of Hydrogen to produce energy is one of the technology under 

study to meet the mankind raising need in energy and as a substitute 

to fossile fuels for the future. This technology is under investigation 

for more than 20 years already, with, for example, the former 

construction of experimental reactors Tore Supra, DIII-D and JET. 

With the construction of ITER to start, the next step to "fusion for 

energy" will be done. In these projects, an extensive use of cryogenic 

systems are requested. Air Liquide has been involved as cryogenic 

partner in most of former and presently constructed fusion reactors. In 

the present paper, a review of the cryogenic systems we delivered to 

Tore Supra, JET, IPR and KSTAR will be presented. 

C4-E-02 Investigation of a test loop for the cooling system 

of the ITER TF coil under pulsed heat load 

B. Rousset, A. Girard, J.M. Poncet, P. Roussel, M. 

Sanmarti, CEA; V. Kalinin, ITER; S. Maze, AREVA; 

D. Murdoch, EFDA. 

The CEA is involved in the design of the cooling scheme of the future 

ITER tokomak. Pulsed operation of ITER will result in heat load 

variations which refrigerators have difficulty to deal with. A load 

smoothing device has been proposed by the ITER team which needs 

to be validated. To do this, a scaled-down experiment (similitude) was 

proposed and studied in the framework of an EFDA sub-task. This 

paper presents the test loop dimensioning and then preliminary design 

for constructing the mock-up. 

The choice of the relevant design criteria had to be defined so as to 

obtain in fine a geometric ratio for similitude. We chose to conserve 

the fluid properties (pressure and temperature) as well as the time 

allocated for the different scenarios. The similitude ratio then relates 

to the heat loads involved for the model and ITER. It is shown that 

this ratio is then applicable for the mass flowrates and also the 

different volumes (heat exchanger, pipes, …) existing on ITER and on 

the future mock-up. 

Once the similitude ratio had been established, the circuit was 

simplified (influence of gravity was ignored and several parallel pipes 

were replaced by an equivalent pipe) while keeping the objective of 

the study, i.e. validating smoothing of the pulsed load. Some 3D 

views corresponding to this preliminary study are presented in this 

paper. 

C4-E-03 Design, analysis and test concept for prototype 

cryo-line of ITER 

B. Sarkar, H. Vaghela, N. Shah, S. Badgujar, R. 

Bhattacharya, Ch. Chakrapani, Institute for Plasma 

Research. 

The ITER cryo-distribution and cryo-line is a part of the in-kind 

supply for India. The design of the systems is in progress. The 

topology of torus and neutral beam cryo-line is defined as six process 

pipes along with thermal shield at 80 K and outer vacuum jacket. In 

order to develop confidence in the concept as well as to establish the 

high level of engineering and manufacturing technology, a prototype 

testing has been proposed. The prototype test will be carried out on 

1:1 model in terms of dimension. However, the mass flow rate of the 

supercritical helium at 4.5 K and gaseous helium at 80 K, will be on a 

1:10 scale. The prototype cryo-line has been designed and analyzed 

for thermal, structural and hydraulic parameters. The prototype will 

simulate the major integrities and technical issues of the cryo-line. 

The objective of this prototype test is to verify mechanical behavior 

due to thermal stress & pressure force, thermal and hydraulic 

performances. The concept of test facility has been realized along 

with the P& I diagram, instrumentation, controls, data acquisition and 

80 K helium generation with warm compressors, primary and 

secondary heat exchangers. The test set up consists of supply and 

receiver valve boxes and interfacing hardware. The test will also 

qualify the analysis tools being used and the deviations. The paper 

will discuss the design concept, methodology for analysis and 

approximations, as well as the test facility. 

Sincere acknowledgement to E. Tada, V. Kalinin 

C4-E-04 Design of the NIF Cryogenic Target System 

C.R. Gibson, General Atomics; B.J. Haid, T.N. 

Malsbury, M.D. Vergino, Lawrence Livermore 

National Laboratory. 

The National Ignition Facility (NIF), with its 192 beamlines focused 

on a tiny target, is the world’s largest laser project. The mission of the 

NIF is to produce high-energy-density conditions and, ultimately, to 

demonstrate fusion ignition through a process called Inertial 

Confinement Fusion. Although many different target designs have 

been proposed, they all include a spherical capsule ~3 mm in diameter 

filled with a mixture of deuterium and tritium (DT). All target designs 

require that the DT is in the form of a solid layer, and hence the target 

temperature must be ~18 K at shot time. 

The purpose of the NIF Cryogenic Target System (CTS) is to field 

cryogenic targets on the NIF. It is designed to cool the targets to 

solidify the DT fuel. Once the DT has formed a smooth layer, the 

target is transported to the center of the NIF Target Chamber and shot. 

The cooling for the CTS is provided by a Gifford-McMahon twostage 

cryocooler. The use of a mechanical cryocooler instead of liquid 

helium does impose design challenges in the area of target 

temperature stability (+/- 2 mK) and target mechanical stability (+/- 

6.8 micron). 

The NIF Cryogenic Target System has completed the Final Design 

phase and a prototype of the cryogenic subsystem has been tested. The 

first CTS production unit is now being fabricated and assembled. This 

paper will present the system design and test results with an emphasis 

on cryogenic design challenges and solutions proposed to meet those 

challenges. 

Work supported by U.S. Department of Energy under Contract No. 

DE-AC0301SF22260 

C4-E-05 Performance of upgraded cooling system for 

LHD helical coils 

S. Hamaguchi, S. Imagawa, T. Obana, N. Yanagi, S. 

Moriuchi, H. Sekiguchi, K. Oba, T. Mito, O. 

Motojima, National Institute for Fusion Science; T. 

Okamura, Tokyo Institute of Technology; T. Senba, 

Hitachi, Ltd.; S. Yoshinaga, H. Wakisaka, 

Ishikawajima-Harima Heavy Industries Co., Ltd.. 

Helical coils of the Large Helical Device (LHD) are large scale 

superconducting magnets for heliotron plasma experiments. The 

helical coils had been cooled by saturated helium at 4.4 K, 120 kPa 

until 2005. An upgrade of the cooling system was carried out in 2006 

in order to improve the cryogenic stability of the helical coils and then 

it has been possible to supply the coils with subcooled helium at 3.2 

K, 120 kPa. A designed mass flow of the supplied subcooled helium 

is 50 g/s. The subcooled helium is generated at a heat exchanger in a 

saturated helium bath. A series of two centrifugal cold compressors 

with gas foil bearing is utilized to lower the helium pressure in the 

bath. The supplied helium temperature is regulated by rotation speed 

of the cold compressors and power of a heater in the bath. The mass 

flow of the supplied helium is also controlled by ten heaters at the 

outlet above the coils. In the present study, the performance of the 

cooling system has been investigated. Although the designed mass 

flow of the subcooled helium at 3.2 K could be supplied to the coils 

stably, the estimated temperature of the coils was higher than 

expected one. The maximum mass flow of the subcooled helium at 

3.2 K was 60 g/s due to the cooling capacity of the cold compressors. 

In this case, the average temperature of the coils is expected to be 

lowered to 3.5 K, which is the designed temperature of the coils after 

the upgrade.

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